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Full text of "American machinists' handbook and dictionary of shop terms : a reference book of machine shop and drawing room data, methods and definitions"

LIBRARY 



^ISSSACHJ;^^^ 




1895 



AMERICAN MACHINISTS' HANDBOOK 



H!i!iPJ!!iSi!i!Him»gM«m¥M»»yg 



"Ms Qraw-TlillBock (h. 7m 

PUDLISH£RS OF BOOKS F O B^ 

Coal Age ^ Electric Railway Journal 
Electrical World v Engineering. News-Record 
American Machinist v The Contractor 
Engineering 8 Mining Journal ^ Power 
Metallurgical 6 Chemical Engineering 
Electrical Merchandising 




American Machinists* Handbook 

AND ' 

DICTIONARY OF SHOP TERMS 

A REFERENCE BOOK OF MACHINE SHOP AND 

DRAWING ROOM DATA, METHODS AND 

DEFINITIONS 



BY 
FRED H. COLVIN 

Member American Society of Mechanical Engineers and Franklin Institute 

Associate editor of the American Machinist, Author of " Machine 

Shop Arithmetic," "Machine Shop Calculations" 

"American Machinists' Grinding Book," 

" The Hill Kink Books," etc., etc. 

and; 
FRANK A. STANLEY 

Member American Society of Mechanical Engineers and Franklin Institute 

Associate editor of the American Machinist, Author of " Accurate 

Tool Work," "Automatic Screw Machines," "American 

Machinists' Grinding Book," " The Hill 

Kink Books," etc. 



SECOND EDITION 
THOROUGHLY REVISED AND ENLARGED 
FOURTEENTH IMPRESSION 
TOTAL ISSUE, 147,000 



McGRAW-HILL BOOK COMPANY, Inc. 
239 WEST 39TH STREET. NEW YORK 



LONDON: HILL PUBLISHING CO., Ltd. 
6 & 8 BOUVERIE ST., E. C. 

1914 



Copyright, 1914, by the McGraw-Hill Book Company, Inc. 
Copyright, 1908, by the Hill Publishing Company 



All rights reserved 



FIRST EDITION 

First Printing, October, 1908 
Second Printing, February, 1909 
Third Printing, May, 1909 
Fourth. Printing, November, 1909 
Fifth Printing, April, 1910 
Sixth Printing, October, 19 10 
Seventh Printing, March, 1911 
Eighth Printing, November. 191:^ 
Ninth Printing, May, 19 12 
Tenth Printing, December, 191a 
Eleventh Printing, April, 19 13 
Total Issue, 36,000 



SECOND EDITION 

First Printing, July, 19 14 
Second Printing, December, 19x4; 
Third Printing, October, 1915 
Fourth Printing, March, 19 16 
Fifth Printing, June, 19 16 
Sixth Printing, October, 1916 
Seventh Printing, March, 1917 
Eighth Printing, June, 19 17 • 
Ninth Printing, October, 19 17 
Tenth Printing, December, 1917 
Eleventh Printing, March, 1918 
Twelfth Printing, May, 1918 
Thirteenth Printing, September, 191? 
Fourteenth Prmting, January, 1919 
Total Issue, 111,000 



C 6 i"^ 



PREFACE TO SECOND EDITION 

Ever since the first printing of this book, the authors have been 
studying waj^s and means of making it better, and the addition of 
one hundred and sixty pages by no means gives an adequate idea 
of the extent to which it has been revised. 

Each section has been carefully studied to make it cover the 
changed and changing conditions of shop and drawing-room work 
in the hope of making it even more valuable than before. 

Many of the changes have been due to suggestions made by users 
of the Handbook, and we shall appreciate a continuance of their 
interest and assistance in pointing out possibilities of improvement. 

The Authors. 






PREFACE TO THE FIRST EDITION 

Every man engaged in mechanical work of any kind, regardless 
of his position in the shop or drawing room, frequently requires 
information that is seldom remembered and is not usually available 
when wanted. 

With this in mind it has been our endeavor to present in con- 
venient form such data as will be of value to practical men in the 
various branches of machine work. While some of the matter in- 
cluded may seem elementary, it was considered necessary in order 
to make the work complete. Much of the information has never 
before been available to the mechanic without tiresome search and 
consultation. 

We believe that the Dictionary section will be found of service 
to the younger mechanics and in helping to estabHsh standard names 
for various parts which are now more or less confused in different 
sections of the coimtry. 

Our indebtedness to various manufacturers and individuals is 
hereby acknowledged, and in the back of the book will be found a 
list of such authorities with page references to the information fur- 
nished by them. 

We dare not hope that no errors will be found and we shall be glad 
to have them pointed out and to receive any suggestions as to addi- 
tions or other changes which may add to the value of the book. 

The Authors. 



CONTENTS 

SCREW THREADS 

Cutting Screw Threads 

Page 

Stud and Lead Screw Gears on Lathe i 

Examples in Finding Gears in Screw Cutting i 

Cutting Fractional Threads i 

Diagram of Simple and Compound Gearing . 2 

Condensed Rules for Screw Cutting 3 

Gears for Screw Cutting 3 

Following Motion of a Train of Gears 4 

Effect of Compound Gearing in the Train 4 

A Screw Thread Angle Table 4 

Side Clearance of Tool for Thread Helix 4 

Formulas for Finding the Angle of Clearance 5 

Use of Protractor in Securing Tool Side Clearance .... 6 

Multiple Thread Cutting 6 

Table of Distances to Move Carriage in Multiple Thread 

Cutting 7 

Opening and Closing the Lead Screw Nut 7 

Face-plate for Multiple Thread Cutting 8 

Cutting Diametral Pitch Worms in the Lathe 8 

Table of Change Gears for Diametral Pitch Worms ... 9 

Examples in Finding Gears for Worm Cutting 10 

The Brown & Sharpe 29-deg. Worm Thread and the Acme 

29-deg. Standard Screw Thread 10 

Full Size Sections of B. & S. Worm and Acme Screw 

Threads, i in. pitch 11 

Measurement of V-Tools 11 

Gear Tooth Caliper as Used for Thread Measurements . . 12 

Table for V-Tool Angle Measurements 13 

Grinding the Flat on Thread Tools 13 

Table of Grinding Flats on Tools for U. S. Form of Thread . 14-15 

• 
Standard Proportions of Screw Threads 

Table of U. S. Standard Screw Threads 16 

Table of Sharp "V" Screw Threads 17 

Table of Whitworth Standard Screw Threads 18 

Table of British Association Screw Threads 19 

Table of French (Metric) Standard Screw Threads .... 20 

Table of International Standard Screw Threads 21 

International Standard Threads 21 

Table of German Loewenherz Threads for Accurate Work. 22 



viii CONTENTS 

Page 

Rolled Threads 23 

Dimensions of Blanks for U. S. S. Rolled Thread Screws . 23 

Table of Acme 29-deg. Screw Threads 24 

Table of Acme 29-deg. Tap Threads 25 

Measuring Screw Threads 

Brown & Sharpe Screw Thread Micrometer Readings for 

U. S. Threads ' . . 26 

Brown & Sharpe Screw Thread Micrometer Readings for 

Sharp "V" Threads 27 

Brown & Sharpe Screw Thread Micrometer Readings for 

Whitworth Threads ; 28 

Explanation of Screw Thread Micrometer Caliper .... 28 

Measuring Thread Diameters with Micrometers and Wires 29 

Measuring Threads of Special Diameter 29 

Formulas for U. S. Thread Measurement with Micrometers 

and Wires 30 

Table for U. S. Thread Measurement with Micrometer and 

Wires 31 

Formulas for Sharp "V" Measurement with Micrometers 

and Wires 32 

Table for Sharp "V" Measurement with Micrometers and 

Wires 33 

Watch Screw Threads 33 

Formulas for Whitworth Thread Measurement with Mi- 
crometers and Wires 34 

Table for Whitworth Screw Measurement with Microm- 
eters and Wires 35 

Measuring Fine Pitch Screw Threads with Micrometers 

and Wires 36 

Constants for 3-wire and Micrometer System of Screw 

Thread Measurement 36 

Measuring Metric Threads with Micrometers and Wires 37 
Constants for 3-wire and Micrometer System of Screw 

Thread Measurement 37 

Measuring Acme 29-deg. Threads 38 

]\Ieasuring Brown & Sharpe 29-deg. Worm Threads 39 

Table of Wire Sizes for Measuring B. & S. Worm Threads . . 39 

Brown & Sharpe 29-deg. Worm Thread Formulas 40 

Table of Brown & Sharpe 29-deg. Worm Thread Parts ... 40 
Table of Wire Sizes for Measuring Acme 29-deg. Screw and 

Tap Threads ' 40 

Worm Wheel Hobs 41 

PIPE AND PIPE THREADS 

Briggs Standard Pipe Threads 42 

Taper of Pipe End and Form of Pipe End in Briggs System 42 

Longitudinal Section of Pipe Thread 42 



CONTENTS ix 

Page 
Dimensions of Wrought Iron Welded Tubes, Briggs Stand- 
ard 43 

Table of British Standard Pipe Threads 44 

Table of Tap Drills for Pipe Threads 45 

Table of Metric Pipe Threads ' . . 45 

The Pipe Joint in the Briggs Standard 46 

Relation of Reamer, Tap, Die and Gages in Briggs System 46 

Forming the Joint in the Briggs System 47 

Table of Briggs Pipe Threads 47-48 

Gage Sets for Briggs Pipe and Fittings 49 

Relation and AppHcation of the Gages 49 

National Standard Hose Coupling 50 

TWIST DRILLS AND TAPS 

Angle of Spiral 51 

Clearance or Relief 51 

Grooves for Best Results 51 

Grinding or Sharpening 52 

Angle of Clearance 52 

High-speed DrilHng 53 

Feeds and Speeds for Various Materials 53 

Data for Drilhng Cast Iron 54 

Horsepower Required to Drill Cast Iron 54 

Drill Troubles and Pointers 55 

Special Drills and Their Uses 55-56 

Standard Types of Drills 57 

Sizes of Drills, Decimal Equivalent and Letter 58-60 

Tap Drill Sizes for Regular Threads 62 

Tap Drill Sizes for A. L. A. M. Threads 62 

Tap Drills for Machine Screw Taps 63 

Twist Drill Dimensions for U. S. Thread Taps 64 

Drills and Reamers for Dowel Pins 64 

Double Depth of Threads 65 

Tap Drills for Taps with "V" Thread 66 

Drill End Lengths 67 



TAPS 

Tapping and Threading Speeds 68 

Dimensions of Machine Screw Taps, Old Standard ... 69 

Machine Screw Taps, Wells Bros. Co 70 

Dimensions of Hand Taps 71 

Dimensions of Tapper Taps 72 

Dimensions of Briggs Standard Pipe Taps 73 

Dimensions of Stove Bolt Taps 74 

Dimensions of Taper Die Taps 75 

Dimensions of Sellers Hobs 76 

Dimensions of Square-Thread Taps 77 



X CONTENTS 

FILES 

Page 

Measurement of Files 78 

Methods of Designating 78 

Terms Used by Makers 78 

Height of Work 78 

Pickling Bath for Work to be Filed 78 

Tooth Spacing 79 

Teeth Per Inch 80 

Shapes and Grades of Files 80-81 

Maximum Efl&ciencies 82 

' WORK BENCHES 

Filing and Assembling Benches 84 

Benches for Average Shop Work 84 

Location of Benches 84 

Modern Designs for Benches 85 

High and Low Cost Benches 85 

Material for Benches 85 

Building Benches from Small Blocks 86 

Height of Work Benches 86 

Width and Thickness of Benches 86 

SOLDERING 

Cleaning the Joint 86 

Strength of Soldered Joint 86 

The Proper Heat for Soldering 86 

Fluxes for Different Metals 86 

Soldering Salts 86 

Fluxes for Sheet Tin 86 

Fluxes for Lead 86 

Lead Burning 87 

Fluxes for Brass ' 87 

Fluxes for Copper 87 

Fluxes for Zinc 87 

Fluxes for Galvanized Iron 87 

Fluxes for Wrought Iron or Steel 87 

Making the Fluxes 88 

Cleaning and Holding the Work . 89 

Soldering with Tin Foil 89 

Soldering Cast Iron 89 

Cold Soldering Various Materials 90 

Solders and Fusible Alloys 90 

Composition and Melting Points of Solders and Fusible 

Alloys 91 

Hard Solders 91 

Aluminum Solders 92 



CONTENTS XI 

GEARING 

Page 

Gear Teeth, Shapes of 93 

Teeth and Parts 93 

Table of Circular Pitch of Gears 94 

Table of Diametral Pitch of Gears 95 

Table of Corresponding Diametral and Circular Pitches. . 96 

Chordal Pitch and Spur Gear Radius . 97 

Table of Constants for Chordal Pitch 97 

Table of Tooth Parts, Diametral Pitch : . . 98-99 

Table of Tooth Parts, Circular Pitch loo-ioi 

Diagram for Cast-Gear Teeth 102 

Laying out Spur Gear Blanks . 103 

Actual Sizes of Diametral Pitches 104-105 

Laying Out Single Curve Teeth 106 

Pressure Angles 106 

La>dng Out Standard Teeth 107 

Stub-tooth Gears 107 

Fellows Stub-tooth Dimensions 108 

Nuttall Stub-tooth Dimensions ^. . . . 108 

Table for Turning and Cutting Gear Blanks .... 109-110 
Table of Pitch Diameters of Standard Gears .... 111-114 

Involute Gear Tooth Cutters 115 

Table of Depth and Thickness of Teeth 115 

Block Indexing in Cutting Gear Teeth 115 

Table for Block Indexing 116 

Metric Pitch, Formula and Table 117 

Sprocket Wheels for Block Center Chains 118 

Sprocket Wheels for Roller Chain 119 

Bevel Gear Parts 120 

Laying Out Bevel Gear Blanks 120 

Proportions of Miter and Bevel Gears 121 

Cutters for Bevel Gears 122 

Table of Dimensions for Miter Gears 123 

Bevel Gear Table and Examples of Use 124-125 

Calculation of Spiral Gears, Table 126 

Laying Out 45-deg. Spiral Gears 127 

Figuring Spiral Gears 128-130 

Real Pitches for Circular Pitch Spiral Gears 131 

Table of Real Pitches for Circular Pitch Spiral Gears . 132-133 

Spiral Gears, Formulas and Rules 134 

Spiral Gear Table 13S 

Chart of Spur Gear Cutters for Spiral Gears 136 

Threads of Worms i37 

Width of Face of Worm Wheels i37 

Finding Pitch Diameter 138 

Table of Worm Threads and Wheels , 139 



xii CONTENTS / 

MILLING AND MILLING CUTTERS 

Page 

Speeds and Feeds for Gear Cutting 140 

Milling Machine Speeds and Feeds 141 

Action of Milling Cutters 142 

Form of Cutter Teeth 143 

Power Required by Cutters . ., 144 

Finish of Work 144 

Chip Breaker 145 

Taper Shank End Mills . 145 

Spiral Shell Cutters . 146 

Wide Spaced Tooth Cutters 147 

Table of Pitches and Angles 148-151 

Cam Milling 

Milling Heart Shaped Cams 152 

Method of Laying Out Cam 152 

Selecting the Cutter 152 

Locating Cam and Cutter at Start 152 

Selecting the Correct Index Plate 152 

Operating the Table for Successive Cuts on the Cam 153 

Mining Cams by Gearing Up the Dividing Head .... 153 

Diagram for Determining Angle of Index Head .... 153 

Gearing the Machine for Cam Lobes of Different Leads 154 

Method of Feeding the Work to the Cutter 154 

Tables of Settings for Milling Screw Machine Cams 155-167 

Indexing 

Plain and Differential Indexing 168 

General Principles of Differential Indexing 1 68-1 71 

Tables of Dividing Head Gears for Indexing 172-189 

Table for Indexing Angles 1 90-1 91 

Milling Cutter Reamer and Tap Flutes 

No. of Teeth in End Mills, Straight and Spiral Flutes . . 192 

No. of Teeth in Inserted Tooth Cutters 192 

Pitch of Metal Slitting Cutters 192 

Pitch of Screw Slotting Cutters ■ . . . 192 

No. of Teeth in Plain Milling Cutters 193 

Form of Cutter for Milling Teeth in Plain Milling Cutters 193 

No. of Teeth in Side or Straddle Mills 193 

Angular Cutter for Milling Teeth in Side or Straddle Mills 193 
No. of Teeth in Corner Rounding Concave and Convex 

Cutters 194 

Angular Cutter for Milling Teeth in Corner Rounding Con- 
cave and Convex Cutters 194 

No. of Teeth in Single and Double Angle and Spiral Mill 

Cutters 194 



CONTENTS xiii 

Page 
Cutter for Milling Teeth in Double Angle and Spiral Mill 

Cutters ^ 194 

No. of Flutes in Taps — Hand, Machine Screw, Tapper, 

Nut and Screw Machine 19S 

Tap Fluting Cutters 196 

No. of Flutes in Taper and Straight Pipe Taps 196 

Fluting Cutters for Taper and Straight Pipe Taps .... 196 

No. of Flutes in Pipe Hobs, Sellers Hobs and Hob Taps . 196 

Fluting Cutter for Hobs 196 

No. of Flutes in Shell Reamers 197 

Cutters for Fluting Reamers 197 

No. of Flutes in Chucking and Taper Reamers 198 

Diameter of Straddle Mills for Fluting Center Reamers 199 

Cutter Key ways, Square and Half-Round 199 

Table of Standard T-Slot Cutter Dimensions 200 

Table of Largest Squares That Can Be Milled on Round 

Stock 200 

Table of Divisions Corresponding to Given Circumferential 

Distances 201 

Table for Milling Side Teeth in Milling Cutters 202 

COLD SAWS 

Cutting Speeds for Cold Saw Cutting-Off Machines . . . 203 

Diagram of Saw Tooth 203 

Table of Cutting Speeds 204 

TURNING AND BORING 

Table for Figuring Machine Time on Turned, Bored or 

Faced Work 205 

Formula for Machine Time on Turned, Bored or Faced 

Work 206 

Calculation of Rotary Cutting Speed 206 

Efi&ciency Tool Tests 206 

Cutting Lubricants for Various Materials 207 



GRINDING AND LAPPING 
Grinding Wheels and Grinding 

Commercial Abrasives: Emery, Corundum, Carborundum, 

and Alundum 208 

Grit and Bond 208 

Bonds of Abrasive Wheels 209 

Grain and Grade 209 

Table of Minimum Thickness of Elastic Wheels 210 

Table of Minimum Thickness of Vitrified Wheels .... 210 

Table of Minimum Thickness of Silicate Wheels 211 

Grading of Wheels 211 



xiv CONTENTS / 

Page 

Selection of Suitable Wheels . ' 212 

The Combination Grit Wheel 212 

Hard Wheels 212 

Wheel Grades for Given Classes of Work 213 

Speed and Efi&cient Cutting 213 

Action of Wheels When Too Hard or Soft 213 

When a Wheel Is Sharp 214 

Contact of Wheels on Different Diameters, Flat Surfaces 

and Internal Work 214 

Selecting Wheels According to Contact 214 

The Contact Area of a Wheel 215 

Wheel Pressure and Wear 215 

Wearing Effect of High Work Speeds 215 

Grinding Allowance, Data 216 

Grinding Hardened Work 216 

Undercut Corners for Shoulders to be Ground 216 

Grinding Allowances for Various Lengths and Diameters 217 

Limit Gage Sizes for Finished Ground Work ....... 218 

Use of Water 218 

Use of Diamonds 218 

Methods of Setting the Diamonds 219 

Table of Grinding Wheel Speeds 220 

Surface Speed of Wheels 221 

Table of Circumferences for Surface Speeds and Revolu-, 

tions 221 

Grading Abrasive Wheels 222 

Grade Marks and Lists of Standard Wheel Makers 222-223 

Table of Grades of Wheels for Different Classes of Work 223 

Shapes of Wheels 224-225 

Mounting Grinding Wheels 226-227 

General Suggestions for Operation 228 

Magnetic Chucks 228 

Hints on Use of Magnetic Chucks 229 

Polishing Wheels 229 

Care of Polishing Wheels 230 

Speeds of Buffing Wheels 230 

Lapping 

Common Classes of Laps 231 

Lapping Plate for Flat Work 231 

Speed of Diamond Laps 231 

Lapping Flat Surfaces 231 

Lubricants in Lapping 232 

Laps for Holes 232 

Adjustable Laps 233 

Advantages of Lead Laps 233 

Various Types of Internal Laps 233 

How to Do Good Lapping 233 

Using Cast Iron, Copper and Lead Laps 233 



CONTENTS XV 

Page 

Ring Gage and Other Work 234 

A Lap for Plugs 234 

Abrasives for Different Kinds of Laps 234 

Diamond Powder in the Machine Shop 234 

Grade of Diamond Used 234 

Reduction Process 234 

Setthng Diamond Powder in Oil 235 

Table for Setding Diamond 235 

Rolling the Diamond Powder into Laps 235 

Diamond Laps 235 

Tools Used in Charging Laps 235 

Diamond Lap for Grinding Small Drills 235 

Grinding Holes in Hard Spindles 236 

Diamond Used on Boxwood Laps 236 

Reamer and Cutter Grinding 

Reamer Clearances ~ 237 

Chucking Reamer Blade for Cast Iron and Bronze ... 237 

Shape of Reamer Blade for Steel 237 

Clearance of Reamer Blades 237 

Grinding the Clearance on Various Classes of Reamers ." . 237 
Table for Grinding Clearances on Different Sizes of 

Reamers 238-239 

Cup Wheel Clearance Table Giving Tooth Rest Settings 

for Desired Clearance 240 

Disk Wheel Clearance Table 240 

OILSTONES AND THEIR USES 

Data on Natural Stones 241 

Data on Artificial Stones 241 

Shapes and Sizes for Machine Shop Use 241-242 

Shapes and Sizes for Mold and Die Work 243 

Care of Oilstones 244 

SCREW MACHINE TOOLS, SPEEDS AND FEEDS 

Box Tools and Cutters 245 

Roughing Box Tool with Tangent Cutter 245 

Clearance for Box Tool Cutters 24,^ 

Sizes of Steel Recommended for Box Tool Cutters .... 246 

Finishing Box Tool with Radial Cutter 246 

Hollow Mills 246 

Location of Cutting Edge and Rake for Hollow Mills . . 246 

Hollow Mill Dimensions 247 

Dies and Taps 247 

Tapping Out Spring Dies 247 

Spring Die Sizes 248 

Sizing Work for Threading 248 



xvi CONTENTS ' 

Page 
Table of Over- and Under-size Allowances for Tapping 

and Threading 249 

Tap Lengths, Number of Flutes and Width of Lands . . 249 

Forming Tool Diameters and Depths 250 

Circular and Dovetail Forming Tools 251 

Cutting Clearances on Forming Tools 251 

Diameters of Circular Tools and Amount Usually Cut 

Below Center 251 

Finishing a Circular Tool to Correct Outline 252 

Formulas for Obtaining Depths to Finish Circular Tool on 

Center Line " 252 

Dovetail Tool Depths 253 

Finishing a Dovetail Forming Tool 253 

Location of Master Tool in Finishing Circular and Dove- 
tail Tools 253 

Circular Tools for Conical Points 254 

Finishing a Circular Tool to Produce a 60-deg. Cone 254 

Finding Diameters of Circular Forming Tools 255 

Table of Dimensions of Cutters for B. & S. Automatic 

Screw Machines 256 

Table for Finding Diameter of Circular Forming Tools for 

B. & S.' Automatic Screw ]\Iachine 256-259 

Hardening Spring Collets and Feed Chucks 260 

Speeds and Feeds for Screw Machine Work 

Table of Cutting Speeds and Feeds for Screw Stock . . . 261 

Table of Cutting Speeds and Feeds for Brass 261 

Table of Speeds and Feeds for Finish Box Tool 262 

Table of Speeds and Feeds for Forming 263 

Table of Speeds and Feeds for Drilling 264 

Table of Speeds and Feeds for Reaming 265 

Table of Speeds and Feeds for Threading 265 

Rate of Feed for Counterboring 265 

PUNCH PRESS TOOLS 

Method of Finding the Diameter of Shell Blanks. .... 266 
Diagrams and Formulas for Blank Diameters for Plain, 

Flanged, Hemispherical and Taper Shells 267 

Formulas and Table of Diameter of Shell Blanks. . . 268-269 

Punch and Die Allowances for Accurate Work 270 

Governing Size of Work by Punch and Die 270 

Table of Clearances for Punch and Die for Different Thick- 
ness and Material 271 

Clearance for Punches and Dies for Boiler Work .... 271 

Lubricants for Press Tools 272 

Oiling Copper and German Silver Sheets for Punching . . 272 

Mixture for Drawing Steel Shells 272 

Preparations for Drawing Brass, Copper, etc 272 



CONTENTS xvii 

BROACHES AND BROACHING 

Page 

Application of Broaching 273 

Shape and Spacing of Teeth for Square Holes 273 

Broaching Round Holes 274 

Saving Time in Broaching Out Square Holes ...... 275 

Broaches for Automobile Transmission Gears 276 

Diagram and Table for Standard Automobile 6-spline 

Fittings 277 

Diagram and Table for Standard Automobile lo-spline 

Fittings 278 

BOLTS, NUTS AND SCREWS 

U. S. Standard Bolts and Nuts 279-281 

Shearing and Tensile Strength of Bolts 279 

Dimensions of U. S. Standard Rough Bolts and Nuts . . 280 

Dimensions of U. S. Finished Bolts and Nuts 281 

Sizes of Machine Bolts with Manufacturers' Standard 

Heads . . 282 

Diagrams of Set Screws 283 

Set Screw Dimensions, Hartford Machine Screw Co.'s 

Standard 283 

Tables of Cap and Machine Screw Dimensions 

Hexagon and Square Head Cap Screws 284 

"Collar Head or Collar Screws 284 

Fillister Head Cap Screws, P. & W. Standard 285 

Flat, Round and Oval Fillister Head Cap Screws .... 286 

Button Head Cap Screws 287 

Flat and Oval Countersunk Head Cap Screws 287 

Flat and Round Head Machine Screws, Amer. Screw Co.'s . 

Standard 288 

Fillister Head Machine Screws, Amer. Screw Co.'s Stand- 
ard 289 

Threads per Inch on Machine Screws, Amer. Screw Co.'s 

Standard 290 

A. S. M. E. Standard Form of Thread, Pitch Formula, etc. 290 
Diagrams of Basic Maximum and Minimum Screw and 

Tap Threads 291 

Tables of A. S. M. E. Standard Machine Screw Dimensions 

Outside, Root and Pitch Diameters of Standard Screws 292 

Diameters of Taps for Standard Screws 293 

Outside, Root and Pitch Diameters of Special Screws . . 294 

Diameters of Taps for Special Screws 295 

Dimensions of Oval Fillister Heads 296 

Dimensions of Flat Fillister Heads 297 



xviii CONTENTS 

Page 

Dimensions of Flat Countersunk Heads 298 

Dimensions of Round or Button Heads 299 

Nut and Bolt Tables 

U. S. Standard Hot Pressed and Cold Punched Nuts . . , 300 

Cold Punched Check and Jam Nuts 300 

Manufacturers' Standard Hot Pressed and Forged Nuts . 301 

Manufacturers' Standard Cold Punched Nuts 302 

Manufacturers' Standard Narrow Gage Hot Pressed Nuts 303 

Whitworth Standard Hexagonal Nuts and Bolt Heads . . 303 

Bolt Heads 

Button Head Machine, Loom and Carriage Bolts .... 304 

Length of Bolts 304 

Length of Threads Cut in Bolts 304 

Round and Square Countersunk Head Bolts 305 

Tap Bolts 305 

Stove Bolts, Diameters and Threads 305 

Automobile Bolt and Nut Standards Adopted by A. L.A.M. 306 

Planer Nuts 307 

CoupHng Bolts 307 

Planer Head Bolts, Nuts and Washers 307 

MISCELLANEOUS TABLES 

Depths to Drill and Tap for Studs 308 

Bolt Heads for Standard T-Slots 308 

Eye Bolts 309 

Spring Cotters 309 

U. S. Standard Washers 310 

Narrow Gage and Square Washers 310 

Cast Iron Washers ■ 311 

Riveting Washers 311 

Machine and Wood Screw Gage Sizes 311 

Coach and Lag Screws 312 

Length of Threads on Coach and Lag Screws 312 

Lag Screvv' Test 312 

Wood Screws 313 

Boiler and Tank Rivet Heads 314 

Length of Round Head Rivets for Different Thicknesses 

of Metal 315 

CALIPERING AND FITTING 

The Vernier and How to Read It 316 

The Vernier Graduations 316 

The Principle of the Vernier Scales 317 

Reading the Micrometer 317 

The Micrometer Parts 317 



CONTENTS XIX 

Page 

The Ten-Thousandth Micrometer 318 

Micrometer Graduations 318 

Measuring Three-Fluted Tools with Micrometer and 
V-block 318-319 

Press and Running Fits 

Parallel Press, Drive and Close Fits 319 

Parallel Running Fits 319 

Table of Limits for Press, Drive and Hand Fits 320 

Table of Limits for Close, Free and Loose Running Fits . . 321 

Shrink Fit Allowances 322 

Limits in Shop Gages for Various Kinds of Fits . . . 322-323 
Limits for Work Ground to Various Classes of Fits . 324-325 

Limits in Plug Gages for Standard Holes 322 

Allowances Over Standard for Force Fits 323 

Allowances Over Standard for Driving Fits 323 

Allowances Below Standard for Push or Keying Fits ... 323 

Clearances of Running Fits 323 

Metric Allowances for Fits of all Classes 325 

Tables of Allowances (INIetric) for Various Classes of Fits 326 

Press Fits for Wheel Hubs 327 

Running Fits for Power Transmission Machinery .... 327 
Making Allowances wdth the Calipers for Various Kinds 

of Fits 328-331 

Side Play of the Cahpers when Measuring for Running Fits 328 
Table of Reduced Diameters Indicated by Side Play of 

Calipers 328 

Axial Inclination of CaUpers in Measuring for Shrink or 

Press Fits 329 

Table of Caliper Inclination for Allowances for Shrink or 

Force Fits 329 

Side Play of Calipers in Boring Holes Larger Than a Piece of 

Known Diameter 330 

Rule for Fiijding Variation in Size of Hole Corresponding to 

Given Amount of Side Play 330 

Allowing for Running and Driving Fits 331 

Dimensions of Keys and Keyseats 

Rules for Key and Key way Proportions 331 

Key and Key way Dimensions 332 

Dimensions of Straight Keys $S3 

Square Feather Keys and Straight Key Sizes 334 

Barth Keys 334 

Pratt & Whitney Key System 335 

Whitney lyeys and Cutters 336 

Proportions of Key Heads 337 

Table for Finding Total Keyway Depths 338-339 

Table of Amount of Taper for Keys of Various Lengths 340 



XX CONTENTS 

TAPERS AND DOVETAILS 

Measuring Tapers 

Page 

An Accurate Taper Gage . 341 

Applications of the Taper Gage 342 

Setting the Adjustable Gage Jaws by Means of Disks . . 342 

Formulas for Use with Taper Gage _ . 343 

Finding Center Distances between the Gage Disks .... 343 

Finding the Disk Diameters 344 

Finding the Amount of Taper per Foot 344 

Finding the Width of Opening at the Ends of the Gage 

Jaws 345 

Diagrams and Tables of Standard Tapers 

Brown & Sharpe Standard Tapers 346-347 

Morse Standard Tapers 348-349 

Morse Taper Short Shanks 350-351 

Standard Tool Co.'s Standard Taper Shanks 352 

Standard Tool Co.'s Short Taper Shanks 353 

Reed Standard Tapers 354 

Jarno Standard Tapers 354-355 

Sellers Standard Tapers 356 

Taper Pins and Reamers 357 

Table of Drill Sizes for Taper Pins 358 

Standard Taper Pins Used by the U. S, Ordnance De- 
partment 359 

Table Giving Total Amount of Taper for Work Tapering 
from o to ij in. per foot and Ranging up to 24 in. 

Long 360 

Table of Tapers Per Foot in Inches and Corresponding 

Angles 361 

Table for Computing Tapers Corresponding to Any Given 

Angle _ 362-363 

Explanation of Table for Computing Tapers 364 

Table for Dimensioning Dovetail Slides and Gibs . . 364-365 

Measuring External and Internal Dovetails 366 

Diagrams of Various Types of Dovetails 366 

Table of Constants for Measuring Dovetails with Plugs . 367 

Examples of Uses of the Table of Constants 367 

Tool for Laying Out Angles Accurately 368 

Table for Setting Tool for Laying Out Angles 368 

Table of Gage Settings for Holes in a Circle 368 

SHOP AND DRAWING ROOM STANDARDS 
Standard Jig Parts 

Drill Bushings 369 

Dimensions of Fixed and Loose Bushings 369 



CONTENTS XXI 

Dimensions of Fixed Bushings for Tools Having Stop 

Collars 370 

Dimensions of Collar Head Jig Screws 370 

Dimensions of Winged Jig Screws 370 

Binding Screws 371 

Supporting and Locking Screws 371 

Dimensions of Nurled Head Jig Screws 372 

Dimensions of Locking Jig Screws 372 

Sizes of Straps for Jigs 372 

Tables of Dimensions of Standard Machine Parts 

Hand Wheels 373 

Handles for Hand Wheels 374 

Knobs 374 

Ball Handles 375 

Binder Handles 375 

Single End Ball Handles 376 

Ball Lever Handles . .• 376 

Wing Nuts 377 

Machine Handles 377 

Thumb Nuts 378 

Hook Bolts 378 

Miscellaneous Tables 

Standard Plug and Ring Gages 379 

Counterbores with Inserted Pilots 380 

Radial Bearings 381 

Thrust Collar Bearings 382-383 

Combined Radial and Thrust Bearings 384-385 

Self-Aligning Radial Bearings 385 

Integral Right-angle Triangles for Erecting Perpendiculars 386 

Construction of Angles from Table of Chords 387 

Chords of Arcs from 10 Minutes to 90 Degrees . . . 388-389 
Table for Spacing Holes in Circles; Diameters i to 12, 

Holes 3 to 32 390-391 

Explanation of Table for Spacing Holes 392 

Table of Sides, Angles and Sines for Spacing 3 to 500 

Holes or Sides in a Circle 392-397 

Lengths of Circular Arcs 398 

Actual Cutting Speeds of Planers with Various Return 

Ratios 399 

Stock Allowed for Standard Upsets 399 

Stock Required to Make Bolt Heads and Nuts, Mfrs' 

Standard Sizes 400 

Stock Required to Make Bolt Heads and Nuts, U. S. 

Standard Sizes 401 

Table of Board Feet in Pieces i to 24 in. Wide Up to 24 

Feet Long . . „ - , 402 



xxii CONTENTS 

Page 

Quick Way of Estimating Lumber for a Pattern 403 

Table of Proportionate Weight of Castings to Weight of 

Pattern 403 

Degrees Obtained by Opening a Two-Foot Rule 403 

Weight of Fillets 404 

Table of Areas or Volumes of Fillets 404 

MISCELLANEOUS INFORMATION 

How to Lay Out a Square Corner 405 

Speeds for Wood Turning 405 

Cooling Hot Bearings 405 

WIRE GAGES AND STOCK WEIGHTS 

Twist Drill and Steel Wire Gage Sizes 406 

Stubs' Gages 406 

Different Standards for Wire Gages in the United States 407 
Wire and Drill Sizes Arranged Consecutively .... 408-409 

Stubs' Steel Wire Sizes and Weights 410 

Music Wire Sizes 411 

Weights of Sheet Steel and Iron, U. S. Standard Gage 411 
Weights of Steel, Iron, Brass and Copper Plates, B. & S. 

Gage 412 

Weights of Steel, Iron, Brass and Copper Plates, B'ham 

Gage . 413 

Weights of Steel, Iron, Brass and Copper Wire, B. & S. 

Gage - 414 

Weights of Steel, Iron, Brass and Copper Wire, B'ham 

Gage 415 

Weights of Steel and Iron Bars per Linear Foot 416 

Weights of Brass, Copper and Aluminum Bars per Linear 

Foot 417 

Weights of Flat Sizes of Steel 418 

Weights of Seamless Brass and Copper Tubing 419 

HORSE-POWER, BELTS AND SHAFTING 

Explanation of Horse-Power 420 

Steam Engine Horse-Power 420 

Electrical Power 420 

Gas Engine Horse-Power 420 

Formula of A. L. A. M. Horse-Power Rating 421 

Table of H. P. Ratings Based on A. L. A. M. Formula . . 421 

Driving Power of Leather Belts 422 

Factors for 180 deg. of Belt Contact 423 

Factors for Varying Degrees of Belt Contact .• 423 

Examples of Power Transmitted by Belts of Varying Sizes 

and Speeds 424 

Data on Pulleys and Ropes 424 



CONTENTS xxui 

Page 

Horse-Power Transmitted by Manila Rope 425 

Data of Manila Transmission Rope 425 

Belt Fastenings • 426 

Belt Hooks 426 

Belt Lacings 426 

Belt Studs 426 

Lacing Belts with Leather 426 

Lacing Belts with Wire 426 

Strength of Lacings 427 

Tension on Belts 427 

AHgning Shafting by a Steel Wire 428-429 

Table of Wire Sag for Lining Shafting 428-429 

Table of Power Transmitted by Steel Shafting 430 

Speeds of Pulleys and Gears 430 

Rules for Finding Pulley and Geared Speeds 431 

Tables of Circumferential Speeds 431-435 

Power Required by Engine Lathes 436 

Power Required by Axle Lathes 436 

Power Required by Wheel Lathes 436 

Power Required by Cylinder Lathes 436 

Power Required by Vertical Boring Mills 436 

Power Required by Horizontal Boring, Drilling and ]\iilling 

Machines 436 

Power Required by Cylinder Boring Machines 436 

Power Required by Miscellaneous Machines 436 

Power Required by Planers 436 

Power Required by Frog and Switch Planers 436 

Power Required by Plate Planers 436 

Power Required by Rotary Planers 437 

Power Required by Shapers 437 

Power Required by Crank Slotters 437 

Power Required by Plain Millers 437 

Power Required by Universal Millers • 437 

Power Required by Vertical Millers 437 

Power Required by Vertical Slab Millers 437 

Power Required by Horizontal Slab Millers 437 

Power Required by Cylindrical Grinders 437 

Power Required by Emery Grinders 437 

Power Required by Miscellaneous Grinders 437 

Power Required by Buffing Heads 437 

Power Required by Vertical Drilling Machines 437 

Power Required by Radial Drilling Machines 438 

Power Required by Multiple Spindle Drilling Machines . 438 

Power Required by Gear Cutters 438 

Power Required by Cold Saws 438 

Power Required by Bolt Cutters 438 

Power Required by Bolt Pointers 438 

Power Required by Nut Tappers 438 

Power Required by Pipe Threading and Cutting-oif 

Machines . 438 



XXIV CONTENTS 

Page 

Power Required by Hammers 438 

Power Required by Bulldozers, Forming or Bending 

Machines • 438 

Power Required by Bolt Headers and Upsetting Machines 438 

Power Required by Hot Nut Machines 439 

Power Required by Hydraulic Wheel Press 439 

Power Required by Bending and Straightening Rolls . . . 439 

Power Required by Notching Press 439 

Power Required by Punches and Shears *. 439 

Motors Usually Employed for Cranes and Hoists .... 439 

Power Required for Planing Mill Equipment 440 

Group Driving of Machines 441 

Power Required for Punching 441 

Power Required to Remove Metal 441 

Factors in Power for Driving Machines 442 

Data and Tables on H. P. to Drive Machines . . . 442-443 



STEEL AND OTHER METALS 

Heat Treatment of Steel 444 

Molecular Changes in Cooling 444 

Safe Temperatures for Steel 444 

Methods of Heating 444 

Furnaces for Different Fuels 444 

Heating in Liquids 444 

Baths for Heating 445 

Gas as Fuel 445 

Cooling the Steel 445 

Baths for Cooling and Hardening 445 

Annealing 446 

Hardening Bath 446 

Bath for Drawing Temper. 447 

High Speed Steels > . 447 

Casehardening 448 

Harveyizing Process 448 

Carbonization or Casehardening 448 

Penetration of Carbon 448 

Carbonizing Materials 449 

Action of Wood Charcoal 449 

Tests of Carbon Penetration 449-450 

Effect of Composition on Strength 451 

Effect of Hardening on Strength 451 

Mechanical Properties When Annealed 451 

Mechanical Properties When Hardened 451 

Quenching Temperatures 452 

Testing Pyrometers 452 

Tests of Hardness 452 

Brinell Test 452 

Table of Brinell Hardness Numerals 453 

Scleroscope Hardness Scale 454 



CONTENTS XXV 

Page 

Fahrenheit and Centigrade Thermometer Scales 455 

Conversion of One Thermometer to the Other 455 

Alloys for Coinage 455 

Composition of Bronzes 456 

Bearing Metals 456 

Bismuth Alloys, Fusible Metals 456 

Alloys 457 

Brass Alloys 457 

Properties of IMetals 458 

Shrinkage of Castings 458 

Aluminum, Properties of 459 

Aluminum, Melting, Polishing and Turning . 459 

STEAM HAMMERS AND DROP FORGING 

Capacity of Steam Hammers 460 

Pressures for Steam Hammers 460 

Boiler Capacity for Steam Hammers 460 

Draft in Drop Forging Dies 461 

Allowances for Shrinkage in Dies 461 

Table of Draft Dimensions 462 

Making Types 462 

Mean Draft of Spherical End of Cyhndrical Type ' . . . 463 

Finishing Semi-circular Impressions 463 

Testing Accuracy of Semi-Circular Impressions 463 

KNOTS, EYE-BOLTS, ROPES AND CHAINS 

Knots and Slings for Handling Work 464-468 

Table of Safe Loads for Eye-bolts 469 

Table of Safe Loads on Ropes and Chains 469 

GENERAL REFERENCE TABLES 

Common Weights and Measures 470-471 

Table of Weights of a Cubic Foot of Substance . . 471-473 

Water Conversion Factors 473 

Convenient Multipliers 474 

The Metric System ' 474 

Metric Weights and Measures 474-475 

Metric and English Conversion Tables 475 

Miscellaneous Conversion Factors 476 

Decimal Equivalents of Fractions of Millimeters, Advan- 
cing by i/ioo mm 476 

Decimal Equivalents of Fractions of Millimeters, Advan- 
cing by 1/50 and i mm 477 

Equivalents of Inches in Millimeters 478 

Decimal Equivalents of Fractions of an Inch,' Advancing 

by 8ths, i6ths, 32ds, and 64ths 479 

Decimal Equivalents of Fractions of an Inch, Advancing 

by 64ths 479 



;xxvi CONTENTS 

Page 

Decimal Equivalents of Fractions Below 1/2 in 480 

Decimal Equivalents of Fractions Between 1/2 and i in. 481 
Decimal Equivalent of Fractions and Nearest Equivalent 

64ths 482-484 

Table of Prime Number Fractions and Their Decimal 

Equivalents 485 

Equivalent of Inches in Decimals of a Foot 486-487 

Squares of Numbers from o to 7 63/64 by 64ths . . . 488-489 
Squares, Cubes, Square and Cube Roots of Fractions from 

1/64 to I in 490-491 

Squares, Cubes, Square and Cube Roots of Numbers from 

I to 1000 492-501 

Areas and Circumferences of Circles from i to 100 . . 502-507 
Areas and Circumferences of Circles from 100 to 1000 508-513 

Circumferences and Diameters of Circles 514 

Reciprocals of Numbers from i to 1000 515-519 

SHOP TRIGONOMETRY 

Explanations of Terms • • • 520-521 

Finding Depth of V-Thread 522 

Finding Diagonal of Bar 522 

Finding Square for Taps 522 

Spacing Bolt Circles 523 

Laying Out Jigs 523 

Trigonometry Formulas 524 

Use of Formulas 524 

Table of Regular Polygons 525 

Practical Examples 526 

Finding Radius Without Center 526 

Properties of Regular Figures: Circle, Triangle, Square, 

Hexagon and Octagon 527-528 

Table of Tangents and Co-tangents 529-540 

Table of Sines and Co-sines 540-551 

Table of Secants and Co-secants 552-563 

DICTIONARY OF SHOP TERMS 

Definitions and Illustrations of Shop Terms 564- -656 

Index 657 



THE AMERICAN MACHINISTS' 
HANDBOOK 

SCREW THREADS 

CUTTING SCREW THREADS 

Nearly all lathes are geared so that if gears ^having the same num- 
ber of teeth are placed on both stud and lead screw, it will cut a thread 
the same pitch as the lead screw. This is called being geared "even." 
If the lathe will not do this, then find what thread will be cut with 
even gears on both stud and lead screw and consider that as the pitch 
of lead screw. In speaking of the pitch of lead screw it will mean 
the thread that will be cut with even gears. 

In cutting the same thread with even gears, both the work and the 
lead screw are turning at the same rate. To cut a faster thread, the 
lead screw must turn faster than the work, so the larger gear goes 
on the stud and the smaller on the lead screw. To cut a slower 
thread (finer-pitch or less lead), the larger gear goes on the screw 
and the smaller on the stud. 

Calling the lead screw 6 to the inch, what gears shall we use- to 
cut an 8 thread? 

Multiply both the lead screw and the thread to be cut by some 
number (the same number for both) that will give two gears you have 
in the set. If the gears vary by 4 teeth, try 4 and get 24 and 32 as 
the gears. If by 5, you get 30 and 40 as the gears. Then as 8 is 
slower than 6, the large gear goes on the lead screw and the small 
one on the stud. 

Cut an 18 thread with a 5-pitch lead screw and gears varying by 
5 teeth. 5 X 5 = 25 and 5 X 18 = 90. There may not be a 90 
gear, but you can use a 2 to i compound gear and use a 45 gear 
instead. That is, put the 25 gear on the stud, use any 2 to i com- 
bination between this and the 45 gear on the screw. 

The 25 gear must drive the large gear of the 2 to i combination 
and the small gear drive the 45-tooth gear, either directly or through 
an intermediate. 

In cutting fractional threads the same rule holds good. To cut 
II J threads with gears that change by 4 teeth, use 4 X 6 = 54 and 
4 X 11^ = 46, with the 24 gear on the stud and the 46 on the screw. 
With gears changing by 5 this is not so easy, as 5 X 115- = 57i> an 
impossible gear. Multiplying by 10 would give 60 and 115, not 
much better. Multiply by 6 and get 6 X 6 = 36 and 6 X ni = 69, 
neither of which is in the set. It seems as though 35 and 70 would 
come pretty near it, but they will cut a 12 thread instead. 

To find what thread any two gears will cut, multiply the pitch of 
lead screw and the gear which goes on it and divide this by the gear 
on the stud. Suppose we try 40 on the stud and 75 on the lead 

I 



SCREW THREADS 




•a 

u 

I 

u 

u 

O O 



SH 



GEARS FOR SCREW-CUTTING 5 

screw. Multiply 75 by 6 = 450 and divide by 40 which gives ii^ 
as the thread that will be cut. Try 45 and 80. 6 X 80 = 480; 
divided by 45 = lof, showing that the 40 and 75 are nearest and 
• that to cut it exactly a special gear will have to be added to the set. 
In reality the gears would not change by 5 teeth with a 6- pitch lead 
screw. 

Rules for screw cutting may be summed up as follows, always 
remem.bering that the lead screw is the thread that will be cut 
when gears having the same number of teeth are placed on both 
screw and stud. 



Having 



A = True lead of screw 

and 
B = Thread to be cut 



To Find 



D 



■■ Gear for stud 

and 
= Gear for screw 



Rule 



Multiply both A and B 
by any one number 
that will give gears 
in the set. Put gear 
A on stud and gear 
B on lead screw. 



A ■= True lead of screw- 
B = Thread to be cut 
C = Gear for stud 



D = Gear for screw 



Multiply B by J and 
divide by A. 



A = True lead of screw 
B = Thread to be cut 
D = Gear for screw 



C = Gear for stud 



Multiply A by D and 
divide by B 



A = True lead of screw 
C = Gear for stud 
D = Gear for screw 



B = Thread that 
will be cut 



Multiply A by D and 
divide by C 



GEARS FOR SCREW-CUTTING 



Gear trains for screw-cutting are usually arranged similarly to 
the illustration, Fig. i. If the gear E on the lathe spindle has the saAe 
number of teeth as the gear H on the stud S, the lathe is geared 
even, i.e., gears having the same teeth placed on both stud and lead 
screw will cut a thread like the lead screw. As shown, the gears 
are out of mesh because the tumbler gears F and G do not mesh with 
E; but moving the handle T down throws F into mesh with E so the 
drive is through E, F, G, H, S and intermediate to L, driving it so 
as to cut a right-hand screw if it is a right-hand thread, as is usually 
the case. Raising handle / cuts out F entirely and reverses the direc- 
tion of the lead screw. 



4 SCREW THREADS 

To follow the motion of a train of gears, take a stick (or your finger 
if they are not running) and trace the motion from the driver to 
the end as shown by the dotted lines in A, B, C and D. 

When a lathe is compound geared the stud gear drives an auxil- 
iary gear as A, which multiplies or reduces the motion as the case 
may be. It will readily be seen, if the stud drives A and B drives L, 
the motion will be exactly doubled because A has one-half the num- 
ber of teeth in B, 



A SCREW-THREAD ANGLE TABLE 

The accompanying table gives the angle of helix of various pitches 
and diameters with respect to a line perpendicular to the axis. These 
angles were worked out with the idea of using them for grinding 
thread tools for threads of various pitches upon different diameters 
of work. This table will enable one to set the protractor at the 
proper angle of side clearance for the work in hand and grind the 
thread tool correctly without guesswork. This is based on the out- 
side diameter. For coarse and multiple threads it is better to figure 
on the pitch diameter. 





Thread Angle Table 



THREADS PER INCH = P 



11 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


n 


12 


5* 


























i: 


50°-54 


32°-3i 


22»-59 


n°-^g 


i4°-i8 


""-59 


io°-i9 


9°-2 


8°-3 


7''-58 


f-ii 


6°- 1 


40-23 


23"- I 


i5^-4« 


I2°-l6 


9°-39 


8°- 8 


7^-13 


6"-37 


5*^-23 


:;"-2o 


4"-40 


4°-24 


i" 


32°-30 


i7°-4i 


ii^-,S« 


9"- 3 


7"- 1 6 


b"-37 


5-40 


4"-33 


4^- 3 


4"- I 


s"-37 


S°- 3 


1" 


27^- 2 


i4;;-i8 


9°-38 


7°-^ 5 


5° -49 


5^« 


4°-io 


3^-52 


3^-15 


3°-i3 


2°-54 


2°-26 


f" 


23°- 5 


I2°- I 


8°- 8 


6^- 4 


4^-52 


4"- 3 


3^-52 


3"- 3 


2°-43 


2°-4I 


2--10 


2°- 2 


i" 


20^^- 4 


I0°-20 


7"^- I 


5°-i2 


4"-io 


3^-28 


2-59 


2°-37 


2--10 


2-^-18 


2"- 4 


T°-SO 


I " 


i7"-30 


^:- ' 


6^- 2 


4^-33 


3^-39 


3"- 2 


2^-36 


2--17 


2°- 2 


2°- 


i°-48 


I°-n 


i|" 


iS"-40 


8^- 4 


.S^-23 


4-- 4 


3^-1^ 


2°-42 


2"-I0 


2"- 2 


i"-48 


i"-47 


i"-37 


T°-2T 


!r 


i4°-io 


7^^-12 


4^-48 


3°-39 


2-55 


2°-26 


2"- 2 


i°-50 


1^-44 


i°-37 


I°-27 


T°-T3 


i.t- 4 


6^^7 


4^-25 


3^-10 


2--40 


2^-13 


i"-54 


i"-36 


I°-29 


I°-28 


i°-iO 


I°-6 


ih" 


11-59 


6^- 4 


4"- 3 


3"- 3 


2°-26 


2°- 2 


1-44 


i°-3i 


l'^-2I 


l"-20 


I"-I3 


T°- T 


if" 


11^- 6 


5^-36 


3-44 


2°-49 


2°-i5 


l"-^2 


i"-36 


l"-2I 


i"-i5 


i"-i4 


i°- 7 


56' 


if" 


IO°-26 


s-^-ib 


3^-20 


2"-37 


2"- s 


i"-44 


l"-20 


i°-i8 


I°-IO 


i"- 8 


I°- 2 


53' 


1 1" 


q"-^o 


4^-52 


3"-!^ 


2"-26 


i"-57 


i°-37 


I°-23 


i"-i3 


i°- 5 


1°- 4 


S8' 


40' 


2 * 


0^- 4 


4"- ^4 


3 - 3 


2°-l8 


i^-So 


i"-3i 


i"-i8 


i"- 8 


i"- I 


T°- 


54' 


4/ 


2}" 


8"- 8 


4"-0 


2"-42 


2"- 2 


i"-37 


l"-2I 


i°- 8 


i"- I 


54' 


w 


49' 


41' 


2?" 


C^-^ 


3°-39 


2°-26 


i°-49 


1^-28 


i°-i6 


^°' ^ 


55' 


49' 


48' 


43' 


•^7^ 


2?" 


b"-,n 


3''-iQ 


2°-i3 


i°-40 


I°-22 


i"- 7 


57' 


so' 


45' 


44' 


40' 


3V 


3 " 


6^^- 4 


3"- 3 


2"- 2 


i"-3i 


i"-i3 


i»- I 


52' 


46' 


41' 


40' 


36' 


3<^* 



A SCREW-THREAD ANGLE TABLE 5 

While the table is worked out for single threads, it can be used for 
double or triple threads by considering the lead equal to the ad- 
vance of the work in one revolution instead of — , as given in the 
table. ^ P 

It is customary in many shops to have several thread tools in stock 
to cut these various thread angles, each cutting within a certain 
range of angles. This table will be useful in determining the best 
range for each thread tool. 



P = Pitch = Threads per inch. — = Lead = L 

C 

D = Diameter of work in inches, tt = 3.1416 = — 

C = Circumference of Work in inches — ir D 



L Lead P t . f a 1 

C = Circumference of Work ^ 7p = ^""^ent of Angle 



Find Angle in Table of Tangents 

Thread Angle Table 
thee ads per inch = p 





























1% 


13 


14 


15 


16 


18 


20 


22 


24 


26 


28 


30 


32 


w 


























i" 


5°-36 


f-^^ 


4''-5i 


4°-33 


4^-3 


3'*-30 


3''-iQ 


3"- I 


2''-45 


2°-s6 


2*^2.? 


20-T7 


-g" 


,s"-45 


3"-28 


3^-14 


3 - 3 


2^-43 


2°- 26 


2°-I3 


2"- I 


I"- S3 


i"-44 


i°-37 


T°-V 


h" 


2"-4Q 


2^^-36 


2^-26 


2-^-17 


2°- 2 


i'^-49 


1--40 


I--SI 


I°-24 


i"-i8 


I°-T^ 


T°- 8 


i" 


2"-I2 


2"- 5 


i"-57 


1--48 


1^^-37 


l"-28 


I°-20 


i°-i3 


i°- 8 


i°- 3 


59 


54 


'\> 


i°-37 


^^44 
i°-30 


i"-37 

l''-24 


i"-3i 
i°-i8 


I°-2I 
I°-IO 


i°- 3 


i'^- 7 
57' 


I"- I 
S3' 


57 
49 


S3' 
■ 45' 


49' 
42' 


IS 


I " 


I°-24 


1^-18 


'!''3 


i°- 8 


l"- I 


55 


•^°, 


45' 


42 


39' 


36' 


34' 


ri" 


i"-iS 


i^-ii 


I"- 5 


i"- I 


^< 


49' 


45^ 


40' 


38 


35' 


32' 


30' 


^t 


^^ 7 


i°- 3 


59 


54' 


49' 


44, 


40 


37' 


34 


31 


29' 


27 


li" 


i°- I 


57' 


53' 


50' 


44' 


40' 


36' 


33 


31 


28' 


27' 


25' 


r¥ 


.0' 


52' 


49 


46 


40' 


36' 


33 


30 


28 


26' 


24' 


2 V 


It 


52 


48' 


45' 


42' 


37 


34; 


3^! 


28' 


26 


24' 


23' 


21' 


48; 


45' 


42 


40' 


35 


3^ 


28' 


26' 


24 


22' 


21' 


19' 


H" 


45' 


42' 


39 


37 


33' 


29' 


27' 


24' 


23 


21' 


19' 


18' 


2 " 


42; 


40' 


3b' 


34' 


31, 


27' 


25' 


22' 


21 


19' 


18' 


1/ 


2t" 


37 


35' 


32' 


30' 


27 


24' 


22 


20' 


19 


18' 


16' 


15' 


21" 


34' 


31' 


29 


27 


24 


22' 


20' 


18' 


17 


15' 


14' 


14' 


2I" 


3^! 


28' 


26' 


25' 


22' 


20' 


18' 


17' 


16 


14' 


iV 


13' 


3" 


28' 


26' 


24' 


23' 


20' 


18' 


17' 


IS' 


14 


13' 


12' 


ll' 



SCREW THREADS 



Figs. 2 and 3 show side and front elevations of the thread to(^ 
and of the protractor as applied to obtain the proper angle of side 
clearance to cut a right-hand screw thread. The front edge of the 
thread tool is used to determine the angle of side clearance. Fig. 4 
shows a section taken along the line a b, Fig. 2. It will be noticed 
that line e f is shorter than G H to give clearance to the cutting 
edges of the thread tool, and also that G R is equal to H R and e S 
is equal to / S. The angle of the hehx at half the depth of the 
thread, Fig. 5, can be used, if desired, and can be approximated to 
from the table, or figured exactly by the method given at the top of 
the table. 




TIG. 2 




FIG. 3 





FIG. 4 ^^^- 5 

The Use of the Protractor 
METRIC THREADS 

Metric threads are measured in millimeter but are calculated by 
the threads per centimeter. Any lathe with a pair of compound or 
''translating gears" with 50 and 127 teeth, can cut metric threads, 
the large gear being driven from the stud. Then the gears for the 
number of threads per centimeter are figured the same as threads 
per inch as on page 3. 

MULTIPLE THREAD CUTTING 

^ The accompan}dng table will be found useful when cutting mul- 
tiple threads. When one thread is cut, the feed nut may be opened 
(the spindle of course being stopped) and the carriage moved along 
by hand the distance given in the table; the nut is then closed on 
the screw and the next thread cut. This is a quick and sure method 
of starting the second, third or fourth thread where the lead screw 
of the lathe is of the pitch given in the table. 



MULTIPLE THREAD CUTTING 



Table for Multiple Thread Cutting 



Cut 


Thread on Lead 
Screw- 


Move Carriage 


DOUBLE 












I 


Even 






J inch 




li 


Any 






2 inch 




li 


Any 






I inch 




2 


4 






J inch 




2i 


Any 






2 inch 




2h 


An}^ 






I inch 




3 


Even 






J inch 




3i 


Any 


' 




2 inch 




3^ 


Any 






I inch 




4 


8 






i inch 




4i 


Any 






2 inch 




4^ 


Any 






I inch 




5 


Even 






^ inch 




5i 


Any 






I inch 




TRIPLE 












I 


6 


iv 


or 


2 threads on 


lead screw 


li 


6 


I^ 


or 


8 threads on 


lead screw 


I^ 


6 


2/y 


or 


4 threads on 


lead screw 


2 


6 


1^ 


or 


I thread on lead screw 


2i 


6 


li'' 


or 


8 threads on 


lead screw 


2h 


6 


f' 


or 


4 threads on 


lead screw 


QUADRUPLE 












I 


4 






iinch 




a 


Any 






I inch 




li 


Even 






J inch 




2 


8 






I inch 




2i 


Any 






I inch 




2i 


Even 






^ inch 





To cut a double thread screw 3I to the inch: the lathe must be 
geared the same as for a single, triple or quadruple thread. The 
tool will of course have to be the same width and the depth of cut 
the same as for a 7 per inch screw. After the first thread is cut it 
will appear very shallow and wide. With the lathe spindle idle, 
the nut is opened and the carriage moved (in either direction) i 
inch; the nut is then closed on the lead screw and the tool is in the 
proper position to make the second cut. 

If the carriage were moved 2 inches, the tool could follow exactly 
the first groove cut. In the case of a triple-thread screw, if the car- 
riage were moved 3 inches, the tool would follow its original path, 
and it would do the same in the case of a quadruple thread if moved 
4 inches. 



8 



SCREW THREADS 



The carriage can, of course, be moved i inch and the nut closed 
no matter what the pitch of the lead screw may be (unless it is frac- 
tional), but in order to close the nut after moving J inch, the screw 
must have some even number of threads per inch. 

As will be seen by referring to the table, a lead screw with any 
even number of threads per inch is used in a number of cases, while 
in several other instances the screw may be of any pitch — either 
odd or even. In certain cases 4 and 8 per inch lead screws are 
specified; and in cutting triple threads a 6 per inch screw is required. 




Fig. 6. — Face-Plate for Multiple Thread Cutting 



FACE-PLATE FOR MULTIPLE THREAD CUTTING 

Fig. 6 shows a face-plate fixture used on various numbers of 
threads. On an ordinary driving plate is fitted a plate having, as 
shown, twelve holes enabling one to get two, three, four or six leads 
if required. This ring carries the driving stud, and is clamped at 
the back of the plate by two bolts as an extra safeguard. All that 
is necessary in operation is to slack off the bolts, withdraw the index 
pin, move the plate the number of holes required, and re-tighten 
the bolts. It is used on different lathes, as occasion requires, by 
making the driving plates alike and drilling a hole for the index pin. 
It is found that the index pin works best when made taper, and a 
light tap is sufficient to loosen or fix it. 



CUTTING DIAMETRAL PITCH WORMS IN THE LATHE 



The .accompanying table is to be used in cases where fractional 
worm- thread cutting is necessary for diametrical pitch worm threads 
to mesh into diametral-pitch worm gears. 



CUTTING DIAMETRAL PITCH WORMS 9 

Table of Change Gears for Diametral Pitch Worms 




t^^A ^i 



At*- 



1^ 


0^ 






Pitch of Lead Screw 


2 


3 


4 


5 


6 


7 


8 


10 


2 I 


078" 


.487" 


.526;' 


¥ 


¥ 


¥ 


¥- 


¥ 


¥ 


¥ 


iffi 


2i 


862" 


•390" 


•421^ 


If 


W 


W 


¥ 


W- 


¥ 


¥b^ 


W 


3 


719" 


•?25" 


•3 so,, 


1! 


¥ 


1! 


W 


¥ 


¥ 


¥1^ 


W 


3i 


616" 


.278" 


.300'/ 


If 


W 


W 


^i 


¥^ 


¥ 


¥^ 


W 


4 


540" 


• 243* 


.263" 


¥ 


ff 


¥ 


!S 


¥ 


¥ 


¥ 


¥ 


S 


431" 


• 195" 


.210" 


II 


if 


If 


¥ 


W 


¥ 


¥^ 


¥ 


6 


360" 


.162" 


•175" 


M 


V- 


ii 


if 


¥ 


¥ 


if 


W 


7 


308" 


• 139" 


• ISO" 


II 


l§ 


II 


W 


¥^ 


¥ 


¥5« 


¥«'^ 


8 


270" 


.122" 


.131" 


il 


if 


¥ 


ft 


H 


¥ 


¥ 


fi 


9 


240" 


. 108" 


.117" 


it 


M 


if 


W 


t! 


¥ 


W 


W 


10 


216" 


■097" 


.105" 


§1 


fi 


It 


V 


If 


¥ 


If 


¥ 


11 


196" 


.088" 


.096" 


f 


f 


f 


V 


¥ 


¥ 


¥ 


¥ 


12 


180" 


.081" 


.088" 


hi 


4J 


M 


If 


¥ 


¥ 


M 


if 


14 


154" 


.069" 


.075" 


11 


II 


n 


If 


II 


¥ 


If 


W 


16 


135" 


.061" 


.066'^ 


M 


li 


if 


11 


If 


H 


¥ 


fi 


18 


120" 


•054" 


.058" 


i§ 


M 


i§ 


II 


i! 


¥ 


II 


¥^ 


20 


108" 


.048" 


.053" 


li 


?3- 


u 


il 


§1 


H 


II 


¥ 


24 


090" 


.040" 


.044" 


II 


U 


M 


if 


e 


H 


M 


l§ 


28 


07/' 


■034" 


.038" 


H 


fi 


If 


II 


If 


ii 


II 


If 


32 


067" 


.030" 


.033" 


H 


m 


M 


m 


If 


H 


ii 


II 


40 


054" 


.024" 


.026" 


*J 


m 


M 


hi 


U 


iS 


if 


H 


48 


045" 


.020" 


.022" 


ii 


U 


a 


T%% 


li 


Ji 


M 


if 



Formula: 



22 X Lead Screw 
7 X Diametral Pitch 



= Ratio of Wheels. 



355 to 113 is more accurate but requires odd gears; a 71 tooth 
gear and a 5 to i compound gives 355. 

In the first column is found the diametral pitch to be cut. In the 
second column is found the corresponding single depth of the worm 
thread. Under the third column is found the width of the tool at 
the point, the tool being the regular 2g-degree included angle. In 
the fourth column is found the width at the top of the worm thread. 

The next heading in the chart is " Pitch of lead screw," and here 
are found different pitches of lead <icrews from 2 to 10. 



10 SCREW THREADS 

Example: Suppose it is desired to cut a worm thread of 4 diametral 
pitch on a single-geared lathe having a 6-pitch lead screw. Now, 
opposite 4 in the first column find the single depth of worm thread, 
or 0.540 inch; and continuing in the same direction from left to 
right, under the next column find the width of the worm-thread tool 
at the point or end, which is 0.243 inch, and so on to the next column 
where is found the width of the worm thread at the top, which is 
0.263 inch. Say there is a 6-pitch lead screw on the lathe. Then 
follow right-on in the same direction until coming to the square 
under 6, and the gear, will be in the ratio of ^j. Of course there is 
no 7 gear on the lathe, so simply bring the fraction ^ to higher 
denominations, say, V X f = If: that is, put the 99 gear on the 
spindle or stud, and the 21 gear on the screw. Then use a gear of 
any convenient size to act as an intermediate gear, and thus connect 
the gear on the spindle with the gear on the screw. Taking the 
fraction ^ and multiplying the numerator and denominator by 4, 
would give VV ^s the two gears to be used. It will be seen that this 
last fraction simply changes the number of teeth in the gears, but 
does not change the value of the fraction; thus there is the same ratio 
of gears. 

Take another case: Suppose it is desired to cut a 20-diametraI 

pitch worm thread in a lathe having a 4-pitch lead screw. What 

would be the necessary gears to cut the desired thread? Next to 

20 in the first column is found the single depth of the worm thread, 

which is 0.108 inch. Continuing on, reading from left to right as 

in the first case, and 0.048 inch is found as the width of the tool at 

the point. In the next column is found the width at the top of the 

worm thread, which in this case is 0.053 inch. Under column 4, and 

opposite 20, are found the gears necessary for cutting a 20-diametral 

pitch worm thread in a lathe with a 4-pitch lead screw. The gears 

2 2 stud 
thus found, nameh', — may not be in the regular set of gears 

•"35 screw 

furnished with the lathe. In that case double up on both and make 

it — ^ , which is the same in value. The two examples thus 

70 screw 
worked out could have been cut on lathes with lead screws having 
any number of threads per inch, with the same result. One point 
in cutting these threads is that the tool must be of exact dimensions 
all over, for if it is not exactly 29 degrees included angle, or the point 
is not as it should be for width, then there will be an error in the 
worm thread all around. 

THE BROWN & SHARPS 29-DEGREE WORM THREAD 

AND THE ACME 29-DEGREE STANDARD 

SCREW THREAD 

There seems to be some confusion among mechanics regarding 
the 29-degree Acme standard screw thread and the Brown & Sharpe 
29-degree worm thread. 

The sketches, Figs. 7 and 8, show plainly the diflference be- 
tween threads of the same pitch in the two systems. The sectional 



MEASUREMENT OF V-TOOLS 



II 



views are of threads of one-inch linear pitch drawn to scale to the 
proportions given by the thread formulas in connection with the 
complete tables of the two systems of threads as given on pages fol- 
lowing. The clearance for bottom of thread is the same, o.oio inch, 
for all pitches. See formula on page 24 for correct dimensions. 




h .6345'-^ ^3655^ 

Fig. 7 ^Acme 29-Degree Screw Thread 




Fig. 8. — Brown & Sharpe 29-Degree Worm Thread 

The worm thread is based on the linear pitch of the worm and 
proportions figured same as rack tooth with varying clearances in 
bottom. B. & S. 29-deg. screw thread has a uniform clearance of 
0.005 inch for all pitches. Do not confuse the two threads. 



MEASUREMENT OF V-TOOLS 

The accompanjdng table of angle measurements should prove of 
convenience to all who make tools for cutting angles or make the 
gages for these tools. 

The principle here adopted is that, on account of the difl&culty 
and in some cases the impossibility of measuring the tool at its point, 
the measurement is taken on the angle of the tool at a given distance 
from the point. In this case the true measurement will be less than 
the actual measurement by an amount equal to twice the tangent of 
half of the angle multiplied by the distance of the line of measure- 
ment from the point. , 



12 



SCREW THREADS 



For making the measurement the Brown & Sharpe gear-tooth 
caliper may be used. Fig. 9 shows this tool in position for measur- 
ing. The depth vernier A is set to a given depth h, and the meas- 
urement is taken by means of the vernier B. The width of the tool 

point X is equal to the measurement on the line a b less 2hl tan. — ) . To 

use the table, h is always taken to be xV i^ch, which is found to be 
a convenient depth for most work. If a greater depth is required, 
all that is necessary is to multiply the figures given by the ratio of 
the required depth to j^ inch. For instance, if the depth is required 




KK 



!^/6 P-1 




Fig. 9. — Measuring Thread Tools 



to be I inch, the figures given are multiplied by 2. In the great 
majority of cases, jq ^'^^^ be found a suitable value for //, when to 
find the width of the point x it is merely necessary to deduct the 

, C 

tan. — 
2 
value of — - — for the angle required, which can be obtained at a 
8 

glance from the table. 

In the case of the Sellers or United States standard thread, the point 
of the tool should be one-eighth of the pitch of the screw, while in 
the Whitworth standard, as shown, the point of the tool would be 
one-sixth of the pitch if it were not rounded. By using these fig- 
ures in combination with the table, it can be determined when suffi- 
cient has been ground from the point of the tool. 

The table is called "Table for Angle Measurements," because if 
a sharp angle, that is, one without the point ground away, is meas- 
ured as above, this measurement, by reference to the table, will give 
the angle direct. 



GRINDING THE FLAT ON THREAD TOOLS 13 

Table for V-Tool Angle Measurements 





c 




c 




c 




/<i>z. — 




tan. — 




tan. - 


Degrees 


2 


Degrees 


2 


Degrees 


2 




8 


8 


8 


I 


O.OOII 


31 


0.0346 


61 * 


0.0736 


2 


0.0022 


32 


0.0358 


62 


0.0751 


3 


0.0033 


33 


0.0370 


63 


0.0766 


4 


0.0044 


34 


0.0382 


64 


0.0781 




0.0055 


35 


0.0394 


65 


0.0796 


6 


0.0066 


36 


0.0406 


66 


0.081 1 


7 


0.0077 


37 


0.0418 


67 


0.0827 


8 


0.0088 


38 


0.0430 


68 


0.0843 


9 


0.0099 


39 


0.0442 


69 


0.0859 


10 


O.OIIO 


40 


0.0454 


70 


0.0875 


II 


O.OI2I 


41 


0.0466 


71 


0.0891 


12 


0.0132 


42 


0.0489 


72 


0.0908 


13 • 


0.0143 


43 


0.0492 


73 


0.0925 


14 


0.0154 


44 


0.0505 


74 


0.0942 


15 


0.0165 


45 


0.0518 


75 


0.0959 


16 


0.0176 


46 


0.0531 


76 


0.0976 


17 


0.0187 


47 


0.0544 


77 


0.0994 


18 


0.0198 


48 


0.0557 


78 


O.IOI2 


19 


0.0209 


49 


0.0570 


79 


0.1030 


20 


0.0220 


50 


0.0583 


80 


0.1048 


21 


0.0231 


51 


0.0596 


81 


0.1067 


22 


0.0242 


52 


0.0609 


82 


0.1086 


23 


0.0253 


53 


0.0623 


83 


O.IIO5 


24 


0.0264 


54 


0.0637 


84 


O.II25 


25 


0.0275 


55 


0.0651 


85 


O.II45 


26 


0.0286 


56 


0.0665 


86 


O.I165 


27 


0.0298 


57 


0.0679 


87 


O.I186 


28 


0.0310 


58 


0.0693 


88 


0.1207' 


29 


0.0322 


59 


0.0707 


89 


0.1228 


30 


0.0334 


60 


0.0721 


. 90 


0.1250 



GRINDING THE FLAT ON THREAD TOOLS 

To facilitate grinding the correct width of flat for the single-point 
inserted tool to cut United States standard form of threads the ac- 
companying table on pages 14 and 15 has been prepared. The dis- 
tance from the point of the tool to the back is first measured with 
the micrometer, then the point of the tool may be ground off until 
the micrometer measurement from the back is equal to the whole 
depth minus dimension Ay when we may be sure, without under- 
taking the difficult job of measuring it directly, that the flat B has 
the proper width. The dimensions A and B for pitches from i to 
64 threads per inch are included in the table. 



X4 



SCREW THREADS 



Table for Grinding Flat End of Tool for Cutting U. S. 
Form of Thread 



..J. 








Threads 
per Inch 


Pitch 


A 


B 


C 


Double 
Depth 


Depth 


I 


1. 000 


.1064 


.125 


.1082 


1.299 


.6495 


2 


.5000 


.0532 


.0625 


.0541 


.6495 


••3247 


3 


'3333 


•0355 


.0416 


.0360 


•433 


•2165 


4 


.2500 


.0266 


.0312 


.0270 


.3247 


.1623 


5 


.2000 


.0213 


.0250 


.0216 


.2598 


.1299 


6 


.1666 


.0177 


.0208 


.0180 


.2165 


.1082 


7 


,1428 


.0152 


.0178 


.0154 


•1855 


.0927 


8 


.1250 


•0133 


.0156 


•0135 


.1623 


.0812 


9 


• nil 


.0118 


.0138 


.0120 


•1443 


.0721 


lO 


.1000 


.0106 


.0125 


.0108 


.1299 


.0649 


II 


.0909 


.00963 


.0113 


.0098 


.1180 


.0592 


12 


.0833 


.00S86 


.0104 


.0090 


.1082 


.0541 


13 


.0769 


.00818 


.0096 


.0083 


.0999 


.0499 


14 


.0714 


.00758 


.0089 


.0077 


.0920 


.0460 


15 


.0666 


.00707 


.0083 


.0071 


.0866 


.0433 


i6 


.0625 


.00673 


.0079 


.0068 


.08 T 2 


.0406 


17 


.0588 


.00620 


•0073 


.0063 


.0764 


.0382 


i8 


.0555 


.005S8 


.0069 


•0059 


.0721 


•0360 


19 


.0526 


.00554 


.0065 


.0056 


.0683 


.0341 


20 


.0500 


.00530 


.0062 


.0054 


.0649 


.0324 


21 


.0476 


.00503 


.0059 


.0051 


.0618 


.0309 


22 


.0454 


.0048 


.0056 


.0049 


.0590 


.0295 


23 


.0431 


.00451 


•0053 


.0046 


.0564 


.0282 


24 


.0416 


•00433 


.0052 


.0045 


.0541 


.0270 


25 


.0400 


.00426 


.0050 


•0043 


.0519 


.0259 


26 


.0384 


.00409 


.0048 


.0041 


.0491 


•0245 


27 


.0370 


•00393 


.0046 


.0040 


.0481 


.0240 


28 


.0357 


•00375 


.0044 


.0038 


.0463 


.0231 


29 


•0344 


.00366 


•0043 


•0037 


.0447 


.0223 


30 


•0333 


.00354 


.0041 


.0036 


•0433 


.0216 


31 


.0322 


•00341 


.0040 


•0035 


.0419 


.0209 


32 


.0312 


.00332 


•0039 


.0034 


•0405 


.0202 



GRINDING THE FLAT ON THREAD TOOLS 



15 



Table for Grinding Flat End of Tool for Cutting U. S. 
Form of Thread 





Threads 
per Inch 


Pitch 


A 


B 


C 


Double 
Depth 


Depth 


33 


.0303 


.00315 


.0037 


.0032 


.0393 


.0196 


■34 


.0294 


•00307 


.0036 


.0031 


.0382 


.0191 


35 


.0285 


.00295 


•0035 


.0030 


.0370 


.0185 


36 


.0277 


.00289 


.0034 


.00295 


.0360 


.0180 


37 


.0270 


.00281 


•0033 


.00286 


.0350 • 


•0175 


38 


.0263 


.00272 


.00325 


.00282 


.0341 


.0170 


39 


.0256 


.00268 


.00320 


.00277 


.0333 


.0166 


40 


.0250 


.00264 


.00312 


.00270 


.0324 


.0162 


41 


.0243 


.00255 


.00303 


.00262 


.0319 


•0159 


42 


.0238 


.00251 


.00295 


.00257 


.0309 


•01545 


43 


.0232 


.00247 


.00290 


.00251 


.0302 


.01520 


44 


.0227 


.00238 


.00283 


.00245 


.0295 


.0147 


45 


.0222 


.00233 


.00277 


.00240 


.0290 


.0145 


46 


.0217 


.00230 


.00271 


.00235 


.0282 


.0141 


47 


.0212 


.00225 


.00265 


.00230 


.0274 


•0137 


48 


.020S 


.00221 


.00260 


.00225 


.0270 


.0135 


49 


.0204 


.00217 


.00255 


.00220 


.0263 


.0131 


50 


.0200 


.00213 


.00250 


.00216 


.0258 


.0129 


51 


.0196 


.00208 


.00245 


.00212 


.0254 


.0127 


52 


.0192 


.00204 


.00240 


.00208 


.0249 


.01245 


53 


.0188 


.00200 


.00235 


.00203 


.0245 


.01225 


54 


.0185 


.00196 


.00231 


.00200 


.02405 


.01202 


55 


.0181 


.00192 


.00226 


.00196 


.0236 


.0118 


56 


.0178 


.00189 


.00222 


.00192 


.0232 


.0116 


57 


•0175 


.00185 


.00218 


.00189 


.0228 


.0114 


58 


.0172 


.00184 


.00215 


.00186 


.0223 


.01115 


59 


.0169 


.00180 


.00211 


.00183 


.02201 


.0110 


60 


.0166 


.00177 


.00208 


.00180 


.02165 


.01082 


61 


.0163 


.00173 


.00203 


.00177 


.02119 


.01059 


62 


.0161 


.00172 


.00202 


.00175 


.02095 


.01047 


63 


.0158 


.00169 


.00198 


.00171 


.02061 


.01030 


64 


.0156 


.00167 


.00196 


.00169 


.02029 


.01014 



l6 SCREW THREADS 

Table of U. S. Standard Screw Threads 
-P a 




[p = Pitch = 



Ho. Threads per Inch 
Formula I d= Depth = p x .64952 

f = riat=-E. 



Diam. 


Threads 


Pitch 


Depth of 


Diam. at Root 


Width of 


of Screw 


to Inch 


Thread 


of Thread 


Flat 


i 


20 


.0500 


•032^ 


.185 


.0063 


T% 


l8 


•0556 


.0361 


.2403 


.0069 


1 


i6 


.0625. 


'^405 


.2936 


.0078 


T? 


14 


.0714 


.0464 


•3447 


.0089 ' 


i 


13 


.0769 


.0499 


.4001 


.0096 


A 


12 


•0833 


.0541 


.4542 


.0104 


t 


II 


.0909 


.0591 


.5069 


.0114 


f 


lO 


.1000 


.0649 


.6201 


.0125 


1 


9 


.ilil 


.0721 


•7307 


•0139 




8 


.1250 


.0812 


.8376 


.0156 


i| 


7 


.1429 


.0928 


•9394 


.0179 


li 


7 


.1429 


.0928 


1.0644 


•0179 


If 


6 


.1667 


.1082 


1-1585 


.0208 


i^ 


6 


.1667 


.1082 


1-2835 


.0208 


If 


5^ 


.1818 


.1181 


1.3888 


.0227 




5 


.2000 


.1299 


1.4902 


.0250 


Is 


5 


.2000 


.1299 


1. 6152' 


.0250 


2 


4\ 


.2222 


.1444 


i^7ii3 


.0278 


2i 


Ah 


.2222 


.1444 


1.9613 


.0278 


2h 


4 


.2500 


.1624 


2.1752 


•0313 


2\ 


4 


.2500 


.1624 


2.4252 


-0313 


3 


3i 


.2857 


.1856 


2.6288 


-0357 


3i 


3h 


.2857 


.1856 


2.8788 


•0357 


3^ 


3i 


•3077 


.1998 


3-1003 


-0385 


3l 


3 


•^^iZ 


.2165 


3-3170 


.0417 


4 


3 


•3333 


.2165 


3-5670 


.0417 


4i 


2i 


.3478 


•2259 


3.7982 


•0435 


4^ 


2l 


.3636 


•2362 


4.0276 


•0455 


4f 


2f 


.3810 


•2474 


4.2551 


.0476 


5 


2^ 


.4000 


.2598 


4.4804 


.0500 


5i 


2^ 


.4000 


.2598 


4-7304 


.0500 


5^ 


2| 


.4210 


•2735 


4-9530 


.0526 


5i 


2| 


.4210 


•2735 


5.2030 


.0526 


6 


2i 


•4444 


.2882 


5-4226 


•0556 



SHARP V THREADS 



17 



Table of Sharp "V" Screw Threads 



p = Pitch = \ 

Formula ^ No. Threads per Inch 




d = Depth = p X .86603 



Diam. 


No. Threads 


Pitch ? 


epth of 


Diam. at Root 


of Screw 


per Inch 


""liread 


of Thread 


I 


20 


.0500 


0433 


.1634 


A 


18 


•0556 


0481 


.2163 


1 


16 


.0625 


0541 


.2667 


tV 


14 


.0714 


0618 


.3140 


h 


12 


•0833 


0722 


•3557 


t\ 


12 


•0833 


0722 


.4182 


t 


II 


.0909 


0787 


.4676 


H 


II 


.0909 


0787 


•5301 


f 


10 


.1000 


0866 


.5768 


if 


10 


.1000 


0866 


•6393 


i 


9 


.iiii 


0962 


.6826 


11 


9 


.iiii 


0962 


•7451 


• I 


8 


.1250 


1083 


.7835 


li 


7 


.1429 


1237 


.8776 


li 


7 


.1429 


1237 


1.0026 


If 


6 


.1667 


1443 


1.0864 


i^ 


6 


.1667 


1443 


1.2114 


If 


5 


.2000 


1733 


1.2784 


If 


5 


.2000 


1733 


1.4034 


i| 


4h 


.2222 


1924 


1.4902 


2 


4h 


.2222 


1924 


1. 6152 


2i 


4h 


.2222 


1924 


1.7402 


2} 


4h 


.2222 


1924 


1.8652 


2f 


4h 


.2222 


1924 


1.9902 


2^ 


4 


.2500 


2165 


2.0670 


2f 


4 


.2500 


2165 . 


2.1920 


2| 


4 


.2500 


2165 


2.3170 


2| 


4 


.2500 


2165 


2.4420 


3 


3h 


•2857 


2474 


2.5052 


3i 


3i 


.2857 


2474 


2.6301 


3i 


3h 


.2857 


2474 


27551 


3l 


3i 


•3077 


2666 


2.8418 


3^ 


3i 


•3077 


2666 


2.9668 ■ 


3f 


3i 


•3077 


2666 


3.0918 


3f 


3 


'3333 


.2886 


3.1727 


3l 


3 


■3333 


.2886 


32977 


4 


3 


■3333 


.2886 


3.4227 



l8 SCREW THREADS 

Table of Whitworth Standard Screw Threads 




fp = Pitch =- 



I No^ Threads pei Inch 

Formula ^ d = Depth = p x .64033 
( r=Eadius=p x .1373 



Diam. of Screw 


No. of 
Threads 
per inch 


Pitch 


Depth of 
Thread 


Diam. at Root 
of Thread 


i 


20 


.0500 


.0320 


.i860 


A 


l8 


•0556 


•0356 


.2414 


t 


i6 


.0625 


.0400 


.2950 


tV 


14 


.0714 


•0457 


.3460 


^ 


12 


•0833 


•0534 


•3933 


t\ 


12 


•0833 


•0534 


•4558 


f 


II 


.0909 


.0582 


.5086 


H 


II 


.0909 


.0582 


•57" 


f . 


lO 


.1000 


.0640 


.6219 


if 


lO 


.1000 


.0640 


.6844 


i 


9 


.IIII 


.0711 


•7327 


I 


8 


.1250 


.0800 


•8399 


li 


7 


.1429 


.0915 


.9420 


li 


7 


.1429 


.0915 


1.0670 


if 


6 


.1667 


.1067 


1.1616 


i^ 


6 


.1667 


.1067 


1.2866 


if 


5 


.2000 


.1281 


1.3689 


If 


5 


.2000 


.1281 


1-4939 


2 


4^ 


.2222 


.1423 


1-7154 


2i 


4 


.2500 


.1601 


1.9298 


2| 


4 


.2500 


.1601 


2.1798 


2| 


3i 


.2857 


.1830 


2.3841 


3 


3i 


.2857 


.1830 


2.6341 


3i 


3i 


•3077 


.1970 


2.8560 


3i 


3i 


•3077 


.1970 


3.1060 


3i 


3 


'3333 


.2134 


3-3231 


4 


3 


'3333 


•2134 


3-5731 


4i 


2| 


.3478 


.2227 


4.0546 


5 


2f 


•3636 


.2328 


4.5343 


5i 


2f 


.3810 


.2439 


5.0121 


6 


2^ 


.4000 


.2561 


5-4877 



BRITISH ASSOCIATION THREADS 
Table of British Association Screw Threads 



19 




rp = Pitch 
Formula < d^ Depth = p x !6 
2 X p 



r = Radius =- 



U 





Diam. 
of Screw 


Approxi- 




I 


Depth 


Diam. 


Num- 


mate F 


itch 


Approximate 


of 


at Root of 


ber 


Diam. n 


am. 


Pitch Inches 1 


hread 


Thread 




mm. 


Inches 






mm. 


inm. 





6.0 


.236 I 





•0394 


6 


4^8 


I 


5-3 


.209 


9 


•0354 


54 


4.22 


2 


4-7 


.185 


81 


.0319 


485 


3^73 


3 


4.1 


.161 


73 


.0287 


44 


3.22 


4 


3-6 


.142 


66 


.0260 


395 


2.81 


5 


3-2 


.126 


59 


.0232 


355 


2.49 


6 


2.8 


.110 


53 


.0209 


32 


2.16 


7 


2-5 


.098 


48 


.0189 


29 


1.92 


8 


2.2 


.087 


43 


^0169 


26 


1.68 


9 


1.9 


•075 


39 


•0154 


235 


1-43 


10 


1-7 


.067 


35 


.0138 


21 


1.28 


II 


1-5 


•059 


31 


.0122 


185 


I -13 


12 


1-3 


.051 


28 


.0110 


17 


.96 


13 


1.2 


.047 


25 


.0098 


15 


•9 


14 


I.O 


•039 


23 


.0091 


14 


.72 


15 


•9 


•035 


21 


.0083 


125 


.65 


16 


•79 


.051 


19 


.0075 


115 


•56 


17 


.70 


.028 


17 


.0067 


10 


•50 


18 


.62 


.024 


15 


.0059 


09 


•44 


19 


•54 


.021 


14 


•0055 


085 


•37 


20 


.48 


.019 


12 


.0047 


07 


•34 


21 


.42 


.017 


II 


.0043 


065 


.29 


22 


•37 


.015 


10 


.0039 


06 


.2.'; 


23 


■33 


.013 


09 


•0035 


055 


.22 


24 


.29 


.oil 


08 


.0031 


05 


.19 


25 


•25 


.010 


07 


.0028 


04 


•17 



20 FRENCH (METRIC) STANDARD SCREW THREADS 

i~^'i^ — J 1^?= Pitch 




{p= Pitch / 

d = Depth = p X .6495 
f=Elat = P- 
Q 



Diameter of 


Pitch 


Diameter at Root 


Width of 


Screw mm. 


mm. 


of Thread mm. 


Flat mm. 


3 


0-5 


2-35 


.06 


4 


0.75 


3-03 


.09 


5 


0-75 


4.03 


.09 


6 


I.O 


4.70 


.13 


7 ^ 


I.O 


5-70 


.13 


8 


1.0 


6.70 


•13 


8 


1.25 


6.38 


.16 


9 


I.O 


7.70 


•13 


9 


1.25 


7.38 


.16 


lO 


1-5 


8.05 


.19 


II 


1-5 


9-05 


.19 


12 


1. 5 


10.05 


.19 


12 


1-75 


9-73 


.22 


14 


2.0 


11.40 


.25 


i6 


2.0 


13.40 


•25 


i8 


2.5 


14-75 


.31 


20 


2-5 


16.75 


.31 


22 


2-5 


18.75 


•31 


22 


3'0 


18.10 


•38 


24 


3-0 


20.10 


.38 


26 


3-0 


22.10 


-38 


27 


3'0 


23.10 


.38 


28 


3-o" 


24.10 


.38 


30 ■ 


3-5 


2545 


•44 


32 


3-5 


2745 


44 


33 


3-5 


28.45 


44 


34 


3-5 


2945 


.44 


36 


4.0 


30.80 


•5 


. 38 


4.0 


32.80 


.5 


39 


4.0 


33-80 


.5 


40 


4.0 


34.80 


.5 


42 


4.5 


36.15 


.56 


44 


4-5 


38.15 


.56 


45 


4-5 


39.15 


.56 


46 


4.5 


40.15 


.56 


48 


5-0 


41.51 


. -63 


50 


5-0 


43.51 


.63 


52 


5-0 


45-51 


'63 


56 


5-5 


48.86 


.69 


60 


5-5 


52.86 


.69 


64 


6.0 


56.21 


.75 


68 


6.0 


60.21 


.75 


72 


6.5 


63.56 


.81 


76 


6.5 


67.56 


.81 


80 


7.0 


70.91 


.88 



INTERNATIONAL STANDARD THREADS 



21 



Table of International Standard Screw Threads 
dimensions in millimeters 




Formula 



rp = Pitch 
<|d = Depth= p 

U 



X .64952 



f =FIat 



Diam. 




Diam. 




Diam. 




Diam. 




of 


Pitch 


of 


Pitch 


of 


Pitch 


of 


Pitch 


Screw 




Screw 




Screw 




Screw 




6 


I.OO 


18 


2.50 


39 


4.00 


68 


6.00 


7 


I.OO 


20 


2.50 


42 


4-50 


72 


6.50 


8 


1-25 


22 


2.50 


45 


4-5° 


76 


6.50 


9 


1.25 


24 


3.00 


48 


5.00 


80 


7.00 


lO 


1.50 


27 


3.00 


52 


5.00 


88 


7-50 


II 


1.50 


30 


3-5° 


56 


5-5° 


96 


8.00 


12 


1-75 


33 


3-50 


60 


6.00 


116 


9.00 


14 


2.00 


36 


4.00 


64 


136 


10,00 


i6 


2.00 















The "International Standard" is the same, with modifications 
noted, as that now in general use in France. 

INTERNATIONAL STANDARD THREADS 

At the "Congress International pour L'Unification des Filetages," 
held in Zurich, October 24, 1898, the following resolutions were 
adopted : 

The Congress has undertaken the task of unifying the threads of 
machine screws. It recommends to all those who wish to adopt the 
metric system of threads to make use of the proposed system. This 
system is the one which has been established by the " Society for the 
Encouragement of National Industries," with the following modi- 
fication adopted by this Congress. 

I. The clearance at the bottom of thread shall not exceed -^ part 
of the hight of the original triangle. The shape of the bottom of 
the thread resulting from said clearance is left to the judgment of 
the manufacturers. However, the Congress recommends rounded 
profile for said bottom. 

3. The table for Standard Diameters accepted is the one which 
has been proposed by the Swiss Committee of Action, (This table 
is given above.) It is to be noticed especially that 1.25 mm. pitch 
is adopted for 8 mm. diameter, and 1.75 mm. pitch for 12 mni. 
diameter. The pitches of sizes between standard diameters indi- 
cated in the table are to be the same as for the next smaller standard 
diameter. 



22 



SCREW THREADS 



/ 



in roOO t^OO O f^ w ^oo ■^ N ^ M moo O lo N O^O H vo ^ fO O Ov O 
<N ro fO 3- 10\0 t^ Ov O M ro "TO OO M •^OC MOO rfl-i 0>10000 f ^ t^ 
OOOOOOOOwHMHMMNOiNrOrO'TlO 10\0 t^ t>-QO 0> 

dddddddddddddddddddddddo'oddd 



VO 00 0> c^ Tj- t^ Oi fOO O "^OO CSvO ^cOw O t^-^tMOO JAOvOrOrOt^ 
OdOwwMHNMcoro^O'*^ lO'O t^oo d\ M CO ■^^ r^ dv M CO •* 

HMHI-ltHMMON 

cjMiot^ ^^u-!C^•*r^O^^C^'*0^'tOlO' O'OO 00 00 oo 00 t^ r^ t^ 

Mt-iM»«HOioicNC)orofOfO*^^io too O r^co 0\0 M cocoioior^ 

qqqoooqooooooooooooooooooqqq 
dddddddddddddddddddddddddddd 



."2^ 
^ 



O 00 fOO O (^ O M M t^ t^ 



ro 0> to (N uooo O ^O PO <N 
^t^w ION Ovt^-+i-(00vO 



OOOOOOOMMMHIMMINMINrO'O'*^ IOM3 !>. t^OO Ov 6 O 

odddddddddddddddddddddddddMw 



M«iot^OOOOOOOOtnOioO>n'+OOOOi 

MHt^cOOOOCSVOt^rOOlN»Ot^O<N>OOl^O>OI 

OOOM-*t^O<MvOO^O> -+00 <N M M O OOC \0 m CO ' 



^ Tt lovO t^oo 00 O 



<5 to •* CO M O^00 O '^ 
•*^ f^O too Looo cs ^j 

M rOcO'^'OO 1^00 O 



0>0 't ( 

O) O CO 1 
CO -*<> 1 



I O O O OOO f- 



O to O O O O I 
to t^ O to O to I 

Ov cOOO M to CO ' 



o o o o o o 
o o o o o o 

CO O r^ ^00 00 






O O 00 t^vo vO to to ■^ CO ' 



00 00 00 oo t^ t^ t^ t^O 'O to 1 

OOvMrototot^O^cor^O^i _ _-- 

OOHWMMMMCSMOtOCOCO^'^tO tO^O t^ t^OO d I 

oooooooooooooooqqoqqqqqwHMHM 
6666666666666666666666666666 



lo to o to o o 



M M CO CO CO 



■ too 



O 00 t^ to • 



OvO coo 'l-CO <N O O 'too <N \D O 
\0 p^ CO f^ ^ M O^O ^ M p^O CO M 
C> C-- io\0 00 O M 00 t^t-t^OOO 
CO ^ too t^ O O w CO to 1 
O O O O O O w 

ddddd ddoooooboooooooooooo 



OOO r^O r}- CO <N M 
. _ . .C^^-to<NOooOT^csOoO 
Mi-(C-)c<<scococo^ too t^ t^oo O O M M 



ROLLED THREADS 



23 



ROLLED THREADS 

The rolled thread process dates back more than 50 years and was 
first patented in England. It was first used on comparatively rough 
work such as track bolts but has come to be used on such fine work 
as the sizing of taps and screws for micrometers. 

The thread is forced up into the dies so that the finished screw is 
larger than the original wire by about the depth of one thread. In 
this way the size of the wire to use for any screw may be found by 
subtracting the depth of one thread from the outside diameter of 



the screw. This is 



.866 



Exact allowance depends on 



threads per inch 
material being roUed and other conditions. 

The dies are usually flat plates of steel, having grooves of the same 
pitch and shape as the thread to be rolled. The dies can be easily 
laid out as follows: 

Draw a horizontal line equal in length to the circumference of the 
wire or blank, and at its end draw a vertical line equal to the lead of 
the screw. The diagonal line made by joining these two points shows 
the angle of incline of the grooves. This can be done more easily if 
both the circumference and the pitch are laid out to ten times their 
actual dimensions. 




Dimensions of Blanks for U. S. S. Rolled Thread Screws 
(Reed & Prince Mfg. Co.) 



Size 


T. P. 1. 


A 


•Size 


T. P. 1. 


A 


i 


40 


.1074 
.1054 


T^6 


12 


•5063 
•5031 


3 




.1586 


5 




.5638 


16 


24 


.1566 


8 




•5605 


i 


20 


•2157 
•2137 


3 
4 


10 


.6828 
.6794 


A 


18 


2745 
.2715 


i 


9 


.8006 
.7972 


1 


16 


•3325 
•3295 


I 


8 


.9165 
•9131 


7, 




.3890 


-r 1 




1.0298 


i¥ 


14 


.3860 


Is 


7 


1.0262 


h 


13 


.4480 
•4450 


li 


7 


1. 1548 
1.1512 



24 



SCREW THREADS 



ACME 29° SCREW THREADS 







=No. of "Threads per Jnoh. 



.D=.5P+.01 
7 =.3707 P 



'W=.3707P— .0058 
S=.0293 P 
B==.6293P f .0052 



The Acme standard thread is an adaptation of the most com- 
monly used style of Worm Thread and is intended to take the place 
of the square thread. 

It is a little shallower than the worm thread, but the same depth 
as the square thread and much stronger than the latter. 

The various parts of the Acme standard thread are obtained as 
follows: 

Width of Point of Tool for Screw Thread = 

.^707 

. ^J—L _ .0052. 

No. of Threads per inch 

.^707 
Width of Screw or Nut Thread 

Diameter of Screw at Root = 

Diameter of Screw 



No. of Threads per inch 

-+.020^. 



Depth of Thread 



No. of Threads per inc 

I 



+ .010. 



2 X No. of Threads per inch 
Table of Acme 29° Screw Thread Parts 



N 


P 


D 


F 


W 


S 


B 










Width of 


Width T 




Number of 


Pitch of 


Depth of 


Width of 


Space at 


of Space 


at Root 


Threads 


Single 


Thread 


^°p °i 


Bottom of 


at Top of 


of . 


per Inch 


Thread 




Thread 


Thread 


Thread 


Thread 


I 


I.O 


.5100 


•3707 


•3655 


.6293 


6345 


li 


•750 


•3850 


.2780 


.2728 


.4720 


4772 


2 


.500 


.2600 


.1853 


.1801 


.3147 


3199 


3 


■Z2>ZZ 


.1767 


•1235 


.1183 


.2098 


2150 


4 


.250 


•1350 


.0927 


.0S75 


•1573 


1625 


5 


.200 


.1100 


.0741 


.06S9 


.1259 


1311 


6 


.1666 


•0933 


.0618 


.0566 


.1049 


IIOI 


7 


.1428 


.0814 


.0529 


.0478 


.0899 


0951 


8 


.125 


.0725 


.0463 


.0411 


.0787 


0839 


9 


.1111 


•0655 


.0413 


.0361 


.0699 


0751 


10 


.10 


.0600 


•0371 


.0319 


.0629 


0681 



ACME 29° TAP THREADS 



25 



ACME 29° TAP THREADS 

UpL^-s — >| I 




N =No. of Threads jwr Inoh' 
P==-^ = Linear Pitch ™ 



W=.3"07P— .0052 
S = .C293P+.0O52 
B =.8293 P +.0052 



t 



The Acme standard tap-thread is cut with the same width of tool 
as the screw -thread and the diameter at the root is the same for tap and 
screw. Clearance at bottom of thread between screw and nut is 
obtained by boring the nut blank .020 oversize. 

The outside diameter of the tap is made .020 larger than the screw 
to give clearance between top of screw-thread and bottom of nut. 

Width of Point of Tool for Tap-Thread = 
.3707 



Width of Thread 



No. of Threads per Inch 
.3707 



.0052. 



No. of Threads per Inch 
Diameter of Screw + .020, 



.0052 



Diameter of Tap 
Diameter of Tap at Root = 

\No. of Threads per Inch 



+ .040. 



Depth of Thread 



2 X No. of Threads' per Inch 
Table of Acme Standard 29° Tap-Thread Parts 



+ .020. 



N. 


P 


D 


F 


W 


S 


B 


Number of 
Threads 
per Inch 


Pitch of 
Single 
Thread 


Depth of 
Thread 


Width of 
Top of 
Thread 


Width of 

Space at 

Bottom of 

Thread 


Width 
of Space 
at Top of 

Thread 


Thickness 

at Root 
of Thread 


I 

li 
2 

3 

4 

1 

7 
8 

9 
10 


I.O 

.750 
.500 

.250 

.200 

.1666 

.1428 

.125 

.nil 

.10 


.5200 

•3950 
.2700 
.1867 
.1450 
.1200 

.0914 

.0825 
•0755 

.0700 


.3655 
.2728 
.1801 
.1183 
.0875 
.0689 
.0566 
.0478 
.0411 
.0361 
.0319 


.3655 
.2728 
.1801 
.1183 
.0875 
.0689 
.0566 
.0478 
.0411 
.0361 
0319 


.6345 
.4772 

.3199 
.2150 
.1625 
.1311 
.1101 
.0951 
.0839 

■0751 
.c68i 


•6345 
.4772 

•3199 
.2150 
.1625 
.1311 
.1101 
.0951 
.0839 

.0751 
.0681 



26 



SCREW THREADS 



Brown & Sharpe Screw Thread Micrometer Caliper 
Readings 



READING OF CALIPER 



ForU. S. Threads =D 



•6495 



U. S. Standard Threads 



s 

.2 
P 


Pitch 


Caliper 
Reading 




i 


Ktch 


Caliper 
Reading 




D 


P 


D -^IfS 


.6495 


D 


P 


J) -6495 


•649s 






P 


P 






P 


P 




64 




.0101 


\ 


20 


.2176 


.0324 




62 




.0105 


♦ 


18 


.2765 


.0360 




60 




.0108 


t 


16 


•3344 


.0406 




58 




.0112 


tV 


14 


•3911 


0464 




56 




.0116 


\ 


13 


.4501 


.0499 




54 




.0120 


^> 


12 


.5084 


.0541 




52 




.0125 


1 • 


II 


.566 


.0590 




50 




.0130 


f 


10 


.6851 


.0649 




48 




.0135 


I 


9 


.8029 


.0721 




46 




.0141 




8 


.9188 


.0812 




44 




.0148 


U 


7 


1.0322 


.0928 




42 




.0155 


I ^ 


7 


1-1572 


.0928 




40 




.0162 


1 1 


6 


1.2668 


.1082 




38 




.0171 


I J 


6 


1.3918 


.1082 




36 




.0180 


If 


5i 


1-507 


.1180 




34 




.0191 


1 1 


5 


1. 6201 


.1299 




32 




.0203 


1 1 


5 


1-7451 


.1299 




30 




.0217 


2 


4i 


1-8557 


.1443 




28 




.0232 


2i 


4 


2-3376 


.1624 




26 




.0250 


3 


3i 


2.8145 


.1855 




24 




.0271 


3i 


3i 


3.3002 


.1998 




22 




.0295 


4 


3 


3-7835 


.2165 



As there is no standard of diameter for the finer pitches, the col- 
umns for diameter and caliper reading are left blank. The column 
on the right gives the number to be subtracted from the diameter to 
obtain the caliper reading. 

For explanation of screw thread piicrometer caliper, refer Xc 
page 28* 



THREAD MICROMETER READINGS 



27 



Brown & Sharpe Screw Thread Micrometer Caliper 
Readings 



READING OF CALIPER 



For "V" Threads =D - 



.866 



'*V" Threads 



i 


Pitch 


CaUper 
Reading 




S 

P 


Pitch 


Caliper 
Reading 








.866 


.866 






^ .866 


.866 


D 


P 


D ^ 


-— - 


D 


p 


D ^ 








P 


P 






P 


"F 




64 




•0135 


i 


24 


.2139 


.0361 




62 




.0140 


i 


20 


.2067 


.0433 




60 




.0144 


i^E 


20 


.2692 


.0433 




58 




.0149 


fa 


18 


.2644 


.0481 




56 




•0155 


f 


18 


.3269 


.0481 




54 




.0160 


I 


16 


.3209 


.0541 




52 




.0167 


7 

T6 


16 


•3834 


.0541 




SO 




.0173 


tV 


14 


.3756 


.0619 




48 




.0180 


h 


14 


.4381 


.0619 




46 




.0188 


h 


13 


•4334 


.0666 




44 




.0197 


h 


12 


.4278 


.0722 




42 




.0206 


♦ 


14 


.5006 


.0619 




40 




.0217 


T% 


12 


•4903 


.0722 




38 




.0228 


f 


II 


•5463 


.0787 




36 




.0241 




10 


.5384 


.0866 




34 




.0255 


H 


10 


.6009 


.0866 




32 




.0271 


f 


10 


.6634 


.0866 




30 




.0289 


7 


9 


.7788 


.0962 




28 




.0309 


I 


8 


.8918 


.1082 




26 




'032,3 


li 


8 


1.0168 


.1082 










li 


7 


1. 1263 


.1237 










I§ 


6 


1-3557 


.1443 



As there is no standard of diameter for the finer pitches, the col- 
umns for diameter and caliper reading are left blank. The column 
on the right gives the number to be subtracted from the diameter to 
obtain the caliper reading. 

For explanation of screw thread micrometer caliper, refer to 
page 28i 



28 



SCREW THREADS 



Brown & Sharpe Screw Thread Micrometer Caliper 
Readings 



reading or caliper 



For Whitworth Threads = D — 



.640 



Whitworth Standard Threads 



Diam. 


Pitch 


Caliper Reading 




D 


P 


.640 


.640 






P 


P 


^ 


20 


.2180 


.0320 


A 


18 


.2769 


•0355 


I 


16 


.3350 


.0400 


14 


.3918 


•0457 


h 


12 


.4467 


•0533 


■3^ 


12 


.5092 


•0533 


f 


II 


.5668 


.0582 


"li 


11 


.6293 


.0582 


^ 


10 


.6860 


• .0640 


^ 


,10 


.7485 


.0640 


i 


9 


.8039 


.0711 


U 


9 . 


.8664 


.0711 




8 


.9200 


.0800 


u 


7 


1.0336 


.0914 




7 


I.1586 


.0914 




6 


1.2684 


.1066 


2 


6 


1-3934 


.1066 


If 


5 


1.4970 


.1280 




5 


1.6220 


.1280 


ll 


4^ 


1.7328 


.1422 


2 


4I 


1.8578 


.1442 


2| 


4i 


1.9828 


.1422 



SCREW-THREAD MICROMETER CALIPER 

The Brown & Sharpe thread micrometer is fitted with pointed 
spindle and "V" anvil as in Fig. 10, to measure the actual thread 
on the cut surface. Enough of the point is removed and the bottom 
of the "V" is carried low enough so that the anvil and spindle clear 
the top and bottom of the thread and rest directly on the sides oi 
the thread. 



MEASURING SCREW-THREAD DIAMETERS 29 

As it measures one-half of the depth of the thread from the top, 
on each side, the diameter of the thread as indicated by the caliper, 
or the pitch diameter, is the full size of the thread less the depth of 
one thread. 

This depth may be found as follows; 

Depth of V threads = .866 -~ number of threads to i" 
" " U. S. Std. " = .6495 ^ " " " " " 
" "Whitworth " =.64 -f- " « « « " 



KZ3 



Fig. 10. — Spindle and Anvil of Thread Micrometer 

As the U. S. thread is flatted | of its own depth on top, it follow^s that 
the pitch diameter of the thread is increased I on each side, equaling 
J of the whole depth and instead of the constant .866 we use the 
constant .6495, which is | of .866. 

When the point and anvil are in contact the o represents a line 
drawn through the plane A B, Fig. 10, 

and if the caliper is opened, say to .500, it represents the distance 
of the two planes .500" apart. The preceding tables are used in 
connection with the micrometer. 

MEASURING EXTERNAL SCREW-THREAD DIAMETERS 
WITH MICROMETERS AND WIRES 

It is frequently necessary, especially in making a tap or thread- 
plug gage, to measure the thread diameter on the thread angle in 
addition to measuring on top of the thread and at the bottom of the 
thread groove, and unless calipers made expressly for such work are 
at hand, the measurement on the thread angle is not made with any 
degree of accuracy or is omitted entirely. The accompanying 
sketches, Figs. 11, 12 and 13, formulas, and tables, are worked out 
for convenience in screw-thread inspection, so that by using ordi- 
nary micrometer calipers and wire of the diameter called for in the 
table the standard threads can be compared with the figures given. 

Threads of Special Diameter 

For threads of special diameter the values of x, Xi or X2 can be 
readily computed from the formula corresponding to the method of 
measuring to be used. The method shown in Fig. 11 at :x: is liable 
to lead to an error unless care be taken that the diameter on top of 
the thread is correct, and also that the flatted surface on the top of 
the threads is concentric with the rest of the thread. The concen- 
tricity of the flatted surface can be tested by measuring, as at x, Fig. 
II, at several points on a plane through the axis and at right angles. 
to it. The wire used must be round and of uniform diameter. 



30 



SCREW THREADS 






fl P xa 





Fig. II. — Measuring U. S. Standard Threads 

D = outside diameter of thread. 
Di = root diameter measured in thread groove. 
n = number of threads per inch of length. 
d = depth of thread. 

p = distance from center to center of adjacent threads. 
/ = width of flat on U. S. Standard thread. 
a = diam^eter of wire used. 

B = distance from apex of thread angle at root, to center of wire, 
Z>2= diameter of cyHnder touched by apexes of thread angles. 
X = diameter from top of threads on one side of tap or bolt, to 
top of wire laid in thread groove on opposite side. 



U. S. Standard Thread 
lead = - , for single threads. 

^x. 6495 =-5^. 



l = i/(Z? -2J)2+ ^ 



Iead\^ 



from p, max; to /> X .505, min. 



B = 



Z)2=r> - 



1-5155 



D D2 ^ a 

X =- + —' + 5 + -, 

22 2 

Xi — D2+ 2 B -\- a. 



s/ 



(D2 + 2 5)2 + 



('f5> 



MEASURING SCREW-THREAD DIAMETERS 



31 



Table for Measuring U. S. Standard Threads with Microm- 
eters AND Wires 



D 


n 


D, 


Da 


a 


B 


C^y 


X 


Xl 


X2 


K 


20 


.1867 


.1742 


.04 


.04 


.000625 


.2721 


.2942 


.2955 


lY 


18 


.2419 


.2283 


.04 


.04 


.000771 


-3304 


-3483 


•3495 


r 


16 


.2954 


.2803 


.04 


.04 


.000976 


.3876 


.4003 


.4016 


tV 


14 


.3465 


.3292 


.04 


.04 


.001274 


.4433 


.4492 


•4507 


V 


13 


.4019 


.3834 


.06 


.06 


.001479 


•5317 


.5634 


•5647 


A' 


12 


.4561 


.4362 


.06 


.06 


.001735 


.5893 


.6162 


.6177 


r 


II 


.5089 


.4872 


.06 


.06 


.002065 


.6461 


.6672 


.6681 


ir 


II 


•5712 


.5497 


.06 


.06 


.002065 


.7086 


-7297 


-7312 


r 


10 


.6221 


.5984 


.06 


.06 


.0025 


-7643 


-7784 


.7801 


w 


10 


.6844 


.6609 


.06 


.06 


.0025 


.8267 


.8409 


.8425 


K 


9 


.7327 


.7066 


O.IO 


O.IO 


.003086 


.9408 


1.0066 


1.0083 


w 


9 


•7950 


.7691 


O.IO 


O.IO 


.003086 


1.0033; 1. 0691 j 1.0706 


i" 


8 


.8399 


.8105 


O.IO 


O.IO 


.003906 


I.0553JI.II05II.II24 


iV 


7 


.9421 


.9085 


O.IO 


O.IO 


.005102 


I.I667JI.2085II.2I07 


li" 


7 


1.0668 


1-0335 


0.10 


O.IO 


.005102 


I.29I7 


^'3335 


I-335S 


ir 


6 


1.1614 


1. 1224 


O.IO 


O.IO 


.006944 


1-3987 


1.4224 


1.4250 


ir 


6 


1.2862 


1.2474 


O.IO 


O.IO 


.006944 


1-5237 


1-5474 


1-5497 


ir 


5^ 


1-3917 


1-3494 


0.15 


0.15 


.008263 


1. 7122 


1.7994 


1.8019 


ir 


5 


1.4935 


1.4469 


0.15 


0.15 


.010 


1.8234 


1.8969 


1.8997 


ir 


5 


1.6182 


1-5719 


0.15 


0.15 


.010 


1.9484 


2.0219 


2.0245 


2" 


4l 


1.7149 


1.6632 


0.15 


0.15 


.012343 


2.0566 


2.1132 


2.1163 


2Y 


4i 


1-8393 


1.7882 


0.15 


0.15 


.012343 


2.I8I6 


2.2382 


2.2411 


^Y 


4l 


1. 9641 


1.9132 


0.15 


0.15 


.012343 


2.3066 


2.3632 


2.3667 


2%" 


4 


2.0540 


1.9961 


0.15 


0.15 


.015625 


2.4105 


2.4461 


2.4495 


2V 


4 


2.1787 


2.1211 


0.15 


0.15 


.015625 


2.5355 


2.5711 


2.5742 


2r 


4 


2.4284 


2.3711 


0.15 


0.15 


.015625 


2.7855 


2.8211 


2.8240 


<. 


^f 


2.6326 


2.5670 


0.20 


0.20 


.020392 


3.0835 


3.1670 


3-1704 


zY 


3f 


2.8823 


2.8170 


0.20 


0.20 


.020392 


3-3335 


3.4170 


3.4200 


zY 


3i 


3.1041 


3-0337 


0.20 


0.20 


.023654 


3.5668 


3-6337 


3.6368 


zk" 


3 


3-32II 


3.2448 


0.20 


0.20 


.02775 


3-7974 


3-8448 


3.8486 


4" 


^. 


3.5708 


3.4948 


0.20 


0.20 


.02775 


4.0474 


4.0948 


4.0983 


4i* 


2r 


3.8019 


3.7228 


0.20 


0.20 


.03024 


4.2864 


4.3228 


4.3264 


aY 


2r 


4.0318 


3.9489 


0.20 


0.20 


.03305 


4.5244 


4-5500 


4.5530 


aV 


2r 


4.2592 


4.1728 


0.20 


0.20 


.03625 


4.7614 


4-7728 


4.7767 


5" 


2^ 


4.4848 


4.3938 


0.20 


0.20 


.040 


4.9970 


4-9938 


4.9980 


5Y 


2^ 


4.7346 


4.6438 


0.20 


0.20 


,040 


5.2470 


5-2438 


5-2477 


€ 


2r 


4.0574 


4.861Q 


0.20 


0.20 


.04431 


5.4810 


5.4619 


5.4661 


If 


2r 


5.2072 


5.1119 


0.20 


0.20 


.04431 


5.7310 


5.7119 


5.7160 


6" 


2Y 


5.4271 5.3264 


0.20 


0.20 


.049373 


5.9632 


5.9264 


5.9307 



32 



SCREW THREADS 



k^-a-->| 




Fig. 12. — Measuring 6o-Degree V-Threads 

D — outside diameter of thread. 
D\ = root diameter measured in thread groove. 
n = number of threads per inch of length. 
d = depth of thread. 

p = distance from center to center of adjacent threads. 
a = diameter of wire used. 

B = distance from apex of thread angle at root, to center of wire. 
i?2= diameter of cyHnder touched by apexes of thread angles. 
X — diameter from top of threads on one side of tap or bolt, to 
top of wire laid in thread groove on opposite side. 



60° V Thread 

P = lead = - , for single threads. 
n 

n 



.866 



, max; to p X -577, min. 



2 



Do^D - 



sin 30° = a. 
1.732 



2 2 2 



Xi 



X2 



D2+ 2B + a. 



/ 



iD,+ 2Br+(^-^y + a. 



MEASURING SCREW-THREAD DIAMETERS 



33 



Table for Measuring 6o-Degree V-Threads with Microm* 

ETERS AND WiRES 



D 


n 


Di 


D3 


a 


B 


Cfy 


X 


Xl 


X2 


i" 


20 


.1653 


.1634 


0.04 


0.04 


.000625 


.2667 


.2834 


.2846 


tV 


i8 


.2180 


.2163 


0.04 


0.04 


.000771 


.3244 


.3363 


.3375 


r 


i6 


.2685 


.2667 


0.04 


0.04 


.0009765 


.3808 


.3867 


.3881 


tV 


14 


.3158 


.3138 


0.06 


0.06 


.0001274 


.4656 


.4938 


.4957 


r 


12 


•3580 


.3557 


0.06 


0.06 


.001735 


.5178 


•5357 


•5375 


^^ 


12 


.4202 


.41S2 


0.06 


0.06 


.001735 


.5803 


.5982 


.5998 


r 


II 


.4697 


.4676 


0.06 


0.06 


.0020657 


.6363 


.6476 


.6492 


w 


II 


.5319 


•530 


0.06 


0.06 


.0020657 


.6987 


.7100 


.7115 


r 


lO 


.5789 


.5768 


O.IO 


O.IO 


.0025 


.8134 


.8768 


.8784 


w 


lO 


.6412 


.6393 


O.IO 


O.IO 


.0025 


.8759 


•93^3 


.9413 


r 


9 


.6847 


.6826 


O.IO 


O.IO 


.003086 


.9288 


.9826 


.9843 


w 


9 


.7470 


.7450 


O.IO 


O.IO 


.0030S6 


.9912 


1.045 


1.0466 


i" 


8 


.7859 


.7835 


O.IO 


O.IO 


.003906 


I.04I7 


1.0835 


1.0854 


ir 


7 


.8803 


.8776 


O.IO 


O.IO 


.005102 


I.I5I3 


1.1776 


1. 1800 


iV 


7 


1.0050 


1.0026 


O.IO 


O.IO 


.005102 


1.2763 


1.3026 


1.3047 


i¥ 


6 


1.0895 


1.0S63 


0.15 


0.15 


.006944 


1.4556 


1.5363 


1.5388 


,l«r 


6 


1.2141 


1.2113 


0.15 


0.15 


.006944 


1.5806 


1.6613 


1.6635 


_5/r 


5 


1.2825 


1.2786 


0.15 


0.15 


.010 


1.6768 


1.7286 


1.7317 


J 4* 


5 


1.407: 


1.4036 


0.15 


0.15 


.010 


I.80I8 


1.8536 


1.8565 


Tr 


4i 


1.4941 


1.490 


0.15 


0.15 


.012343 


1-9075 


1.9400 


1.9434 


2" 


4^ 


1.6188 


1. 615 


0.15 


0.15 


.012343 


2.0325 


2.0650 


2.0682 


21" 


4l 


1-7435 


1.740 


0.15 


0.15 


.012343 


2.1575 


2.1900 


2.1930 


2V 


4^ 


1.8683 


1.8651 


0.15 


0.15 


.012343 


2.2S25 


2.3150 


2.3178 


21" 


4h 


1.9930 


1.990 


0.15 


0.15 


.012343 


2.4075 


2.440 


2.4426 


2V 


4 


2.0707 


2.067 


0.20 


0.20 


.015625 


2.5835 


2.670 


2.6670 


2i" 


4 


2.3203 


2.317 


0.20 


0.20 


.015625 


2.8335 


2.917 


2.9196 


3" 


3^ 


2.5089 


2.505 


0.20 


0.20 


.020392 


3.0525 


3.105 


3-1085 


3V 


3h 


2.7587 


2.755 


0.20 


0.20 


.020392 


3.3025 


3-355 


3-3582 


3r 


3i 


2.9711 


2.967 


0.20 


0.20 


.023654 


3.5335 


3.567 


3-5705 


•sr 


3 


3.1770 


3-1727 


0.20 


0.20 


.02775 


3.7613 


3.7727 


3-7765 


4" 


3 


3.4266 


3.4227 


0.20 


0.20 


.02775 


4.01 13 


4.0227 


4.0263 






WATCH SCREW THREADS 




Wai 


CH SCI 


ew threads are of sharp V-form and gener 


ally 45-degree 


angle f 


or sen 


iws used in nickel and brass; though 60 d 


egrees for use 


in stee 


I. Th 


e Waltham Watch Company and others 


use the centi- 


meter 


as the 


unit for all measurements with the exc 


eption of the 


pitch, 


which 


is based on the inch; the Waltham three 


ds being no, 


I20, I^ 


^o, 1 6c 


), 170, 180, 200, 220, 240, 254, per inch £ 


md the diam- 


eters r 


anging 


from < 


3. 1 20 t( 


> 0.03 


5 cm. 











34 



SCREW THREADS 



I* -a. J 




Fig. 13. — Measuring Whitworth Threads 

D = outside diameter of thread. 
Di= root diameter measured in thread groove. 
n = number of threads per inch of length. 
d = depth of thread. 

p = distance from center to center of adjacent threads. 
r = radius on Whitworth thread. 
a = diameter of wire used. 

B = distance from apex of thread angle at root, to center of wire. 
D2= diameter of cylinder touched by apexes of thread angles. 
X — diameter from top of threads on one side of tap or bolt, tc 
top of wire laid in thread groove on opposite side. 





Whitworth Thre.\d 


p 


= lead = -, for single threads. 


d 


= ^X.64033=^^- 


Di 


..0z._,,)3 + (l£^y. 


r 


-PX .1373- 


a 


= p X .84, max; to ^ X -454, min. 


B 


= - -T- sm 27° 30' = -. 

2 ' ^ .9235 


D. 


1.600825 



2 2 2 



D2+ 2B + a. 



~^(D,+ .By + (l^'y + 



a. 



MEASURING SCREW-THREAD DIAMETERS 



35 



Table tor Measuring Whitworth Threads with Micrometers 
AND Wires 



D 


n 


Di 


D2 


a 


B 


(^!r 


X 


Xl 


X2 


r 


20 


.1875 


.1699 


0.04 


•04331 


.000625 


.2733 


•2965 


•2977 


■h" 


i8 


.2428 


.2235 


0.04 


•04331 


.000771 


•3313 


•3501 


•3514 


¥ 


i6 


.2965 


.2749 


0.04 


.04331 


.000976 


'3^^?> 


.4015 


.4029 


iV 


14 


.344 


•3231 


0.04 


•04331 


.001274 


.4436 


.4497 


.4512 


¥ 


12 


•3953 


.3666 


0.06 


.06496 


.001735 


•5232 


.5563 


.5582 


rV 


12 


•4576 


.4291 


0.06 


.06496 


.001735 


•5907 


.6190 


.6204 


r 


II 


.5105 


•4794 


0.06 


.06496 


.002065 


•6372 


.6693 


.6710 


w 


II 


.5728 


.5420 


0.06 


.06496 


.002065 


.7097 


•7319 


•7334 


r 


lO 


.6239 


.5899 


0.06 


.06496 


.0025 


.7649 


.7798 


.7815 


w 


lO 


.6862 


.6524 


0.06 


.06496 


.0025 


.8274 


.8423 


.8438 


V 


9 


.7348 


.6971 


0.06 


.06496 


.003086 


.8810 


.8870 


.8882 


w 


9 


.797 


•7596 


C.06 


.06496 


.003086 


•9435 


.9495 


.9512 


/r 


8 


.8422 


.7999 


O.IO 


.I0S39 


.003906 


1.0583 


1.1167 1.1185 


ir 


7 


.9447 


.8963 


O.IO 


.I0S39 


.005102 


1. 169 


1.2131 


1. 2153 


ir 


7 


1.0693 


1.0213 


O.IO 


.10839 


.005102 


1.294 


1.3381 


1.340 


ir 


6 


1. 1644 


1. 1082 


O.IO 


.10839 


.006944 


1.400 


1.4250 


1.4276 


iV 


6 


1.2892I1.2332 


O.IO 


.I0S39 


.006944 


1.525 


i.55ooli.5523 


ir 


5 


1. 3 7 26] 1. 3 048 


0.15 


.16242 


.010 


1.7023 


1. 7796'!. 7826 


iV 


5 


1.497 


1.4298 


0.15 


.16242 


.010 


1.8273 


1.9046 1.9074 


T 'f 


a\ 


1.5942 


1-5193 


0.15 


.16242 


.012343 


1-9345 


1.9941 


1-9973 


2" 


4i 


1.7185 


1.6443 


0.15 


.16242 


•012343 


2.0595 


2.1191 


2.1221 


2Y 


4i 


1-8437 


1.7693 


0.15 


.16242 


•012343 


2.1845 


2.2441 


2.2470 


2V 


4 


1-9338 


1.849S 


0.15 


.16242 


.015625 


2.2873 


2.3246 


2.328 


2r 


4 


2.0585 


1-9750 


0.15 


.16242 


.01562512.4123 


2.4498 


2-453 


2¥ 


4 


2.1833 


2.100 


0.15 


.16242 


.015625 2.5373 


2.5748 


2.5778 


2r 


3l 


2.3882 


2.2926 


0.20 


.21567 


.020392 2.837 


2.9240 


2.9276 


s'^ 


3i 


2.6397 


2.5426 


0.20 


-21567 


.020392 3.087 


3.1740 


3-1773 


3r 


3i 


2.860 


2-7574 


0.20 


.21567 


.023654 3.3194I3.3887 


3-3924 


3r 


3i 


3.1098 


3.0074 


0.20 


.21567 


.02365413.5694,3.6387 


3.642 


sr 


3 


3.327 


3.2164 


0.20 


-21567 


.027755 


3-799 


3.8477 


3.8515 


4^ 


3, 


3.5768 


3.4664 


0.20 


.21567 


.027755 


4.049 


4.0977 


4.1012 


4r 


2| 


3.808 


3-693 


0.20 


-21567 


.030241 


4.287 


4.3243 


4-328 


4r 


2f 


4.0582 


3.943 


0.20 


-21567 


.030241 


4-537 


4-5743 


4.578 


4f 


2f 


4.2878 


4.168 


0.20 


.21567 


-033051 


4.7746 


4-7993 


4.8025 


S" 


2f 


4-5376 


4.418 


0.20 


.21567 


.033051 


5-0245 


5.0493 


5.0524 


sY 


- 2f 


4-7658 


4.640 


0.20 


.21567 


.036252 


5.2607 


5.2713 


5.275 


S¥ 


2| 


5-0156 


4.890 


0.20 


.21567 


.036252 


5-5107 


5-5213 


5-5248 


sr 


2j 


5-2415 


5. no 


0.20 


.21567 


.040 


5-7455 


5-7413 


5-7446 


6" 


2\ 


5-4913 


5-360 


0.20 


.21567 


.040 


5-9955 


5.9913 


5-9944 



36 



SCREW THREADS 



MEASURING FINE PITCH SCREW-THREAD 
DIAMETERS 

The accompanying table should be of service to those using the 
three-wire system of measurement as the constants cover the finer 
pitches and may be easily applied to screw threads of any diameter. 
The diagrams, Fig. 14, make the method of application so plain 
that no description appears necessary. 




Formulas: 

For V Thread For Sellers Thread 

D = (M - 3 W) + 1.732 P. D = (M - 3 W) + 1. 5155 P. 

M = (D - 1.732 P) + 3 W. M = (D - 1.S155 P) + 3 W. 

Fig. 14. — Measuring Fine Pitch Threads 

Constants for Use with the 3-W1RE System of Measuring 
Screw Threads 



Threads 
per Inch 


For 
V Thread 
1.732 P = 


For SeUers 

Thread 
1.515s P= 


Threads 
per Inch 


For 
V Thread 
1.732 P = 


For Sellers 

Thread 
1-5155 P = 


8 


.21650 


.18943 


25 


.06928 


.06062 





.19244 


.16839 


28 


.06185 


.05412 


10 


.17320 


.15155 


32 


.05412 


.04736 


II 


•15745 


•13777 


36 


.04811 


.04210 


12 


.14433 


.12629 


40 


.04330 


.03789 


13 


.13323 


.11658 


48 


.03608 


.03157 


14 


.12371 


.10825 


50 


.03464 


.03031 


16 


.10825 


.09472 


56 


.03093 


.02706 


18 


.09622 


.08419 


64 


.02706 


.02368 


20 


.08660 


.07578 


80 


.02165 


.01894 


22 


.07872 


.06889 


100 


.01732 


.01516 


24 


.07216 


.06314 









MEASURING METRIC THREADS 



37 



* MEASURING METRIC SCREW THREAD 
DIAMETERS 

The tables and formulas given herewith in connection with Fig. 15 
should be of value to those engaged in work requiring the frequent 
production of thread gages or special taps in the metric sizes. The 
three wire system is used as in the preceding tables, the wires being 
appHed as indicated. 




Formulas: 



For V Threads 



D = (M - 3 W) + 1.732 P. 
M = (D - 1.732 P.) +3W. 



For Threads with Flat Top 
and Bottom equal to 5 of 
the Pitch 

D = (M -3W) +1.SISS P. 

M = (.D - i.siSS P.) 4- 3 W. 



Fig. 15. — Measuring Metric Threads 

Constants for Use in Measuring Metric Screw Threads 

BY the 3-W1RE System 



Pitch 
m-m 


Pitch 
Inches 


1.732P 


I-5I55P 


Pitch 
m-m 


Pitch 
Inches 


1.732P 


t.5i55P 


o.S 

0.75 

I.O 


.01969 
•02953 
.03937 


.03410 
.05109 
.06819 


.02984 
•04475 
.05966 


4.5 
5.0 
5-5 • 


.17717 
.19685 
.21654 


.30686 
.34094 
•37500 


.26850 
29833 
32816 


1.25 

1-5 

1-75 


.04921 
.05900 
.06890 


.08523 
.09719 
• 11933 


.07458 
.08941 
.10442 


6.0 
6.5 

7.0 


.23622 
•25591 
•27559 


.40913 
•43773 
.47677 


38783 
41766 


2.0 

2.5 

30 


.07874 
.09843 
.11811 


.13638 
.16948 
.20456 


•11933 
.14917 
.17899 


7-5 
8.0 
9.0 


.29528 
•31496 

•35433 


•51092 
.54551 
.60870 


44749 
47732 
53699 


3-5 
4.0 


.13780 
•15748 


.23867 
.26775 


.20784 
.23866 


10.00 


.39370 


.68189 


5966s 



3^ 



SCREW THREADS 



MEASURING ACME 29-DEGREE THREADS 

The diameter of a wire which will be flush with tops of thread on 
tap when laid in the Acme thread groove, Fig. 16, will be found as 
follows: 

Rad, ci wire section = side opp. = side adj. X tan. 37° 45' = 
/. X. 6.93+ -005^ ^_^^^^3, 

Diam. of wire = (p X .6293 + .0052) .77428. 

Wires of the diameter given in the table come flush with the tops 
of tao threads and project .010 above the top of screw threads. 



, Tap Thread 

^ — ^ — H h- 



A 




Fig. 16. — Measuring Acme Threads 



Table op Wire Sizes for Measuring Acme St.\ndard 29° Screw 
AND Tap Threads 



Threads per Inch 


Pitch 


Diam. of Wire 


I 


I. 


0.4913 


li 


•750 


0.3694 


ih 


.6666 


0.3288 


If 


.5774 


0.2824 


2 


.500 


0.2476 


2h 


.400 


0.1989 


3 


'3333 


0.1664 


4 


.250 


O.125S 


s 


.200 


O.1014 


6 


.1666 


0.0852 


7 


.1428 


0.0736 


8 


.125 


0.0649 


9 


.iiii 


0.0581 


10 


.100 


0.0527 


^ 







MEASURING 29-DEGREE WORM THREADS 39 

MEASURING BROWN & SHARPE 29-DEGREE 
WORM THREADS 

The diameter of wire for Brown & Sharpe worm thread, Fig. 17, 
for each pitch, that will rest in the thread groove on the thread angle 
and be flush with the tops of the finished threads, is found as follows; 

Rad. of wire section (see table) = side opp. = side adj. X tan. 

37° 46' = -^ — ^ — X 0.77428 = 0.257448 P and diam. of wire = 
0.5149 P- 




Fig. 17. — Measuring Brown & Sharpe Worm Threads. 



Table of Wire Sizes for Measuring B. & S. 29° Worm Threads 



Threads per Inch 


Pitch 


Diam. of Wire 




h 


2. 


1.0298 




f 


1-750 


0.9010 




f 


1.500 


0.7723 




1 


1.250 


0.6436 




I 


I.O 


0.5149 




ih 


.6666 


0.3432 




2 


•5 


0.2574 




2| 


A 


0.2060 




3, 


•Z333 


O.1716 




3i 


.2857 


O.1471 




4 


.250 


0.1287 




4i 


.2222 


O.I144 




5 


.2 


0.1030 




6 


.1666 


O.0S58 




7 


.1428 


0.0735 




8 


.125 


0.0643 




9 


.iiii 


0.0572 




ro 


.10 


0.0515 




12 


'<^^3Z 


0.0429 




16 


.0625 


0.0322 




20 


.050 


0.0257 . 


__ 



40 



WORM THREADS 




of Threads per Tnch. 
= Linear Pitch 



S — .665 P 
B=.69P 



Pitch = 



Depth of Thread 



No. of Threads per inch 
.6866 



Width of Top of Thread 
Width of Space at Bottom 
Clearance at Bottom of Thread 
Width of Space at Top of Thread = 
Thickness at Root of Thread = 



No. of Threads per inch' 

-335 



No. of Threads per inch 
.310 



No. of Threads per inch 
Thickness at Pitch Line 



10 
.665 



No. of Threads per inch 
.69 



No. of Threads per inch 
Table of Brown & Sharpe 29° Worm Thread Parts 





P 


D 


F 


w 


T 


A 


c 


s 


B 


III 




2^ 


111 


•5 82 

mi 




"1 


e £ S 


-0% 
•5 S 


III 


I 


I.O 


.6866 


•3350 


.3100 


.5000 


.3183 


•05 


.66=; 


.69 


li 


.8 


•5492 


.2680 


.2480 


.4000 


.2546 


.04 


.532 


.552 


li 


.6666 


•4577 


.2233 


.2066 


•3333 


.2122 


•0333 


•4433 


•4599 


2 


•5 


•3433 


•1675 


.1550 


.2500 


.1592 


.0250 


.3325 


.345 


2i 


.4 


.2746 


.1340 


.1240 


.2000 


.1273 


.0200 


.2660 


.276 


3 


'3333 


.2289 


.1117 


•1033 


.1666 


.1061 


.0166 


.2216 


.2299 


3i 


.2857 


.1962 


•0957 


.0886 


.1429 


.0909 


.0143 


.1901 


.2011 


4 


.250 


.1716 


.0838 


•0775 


.1250 


.0796 


.0125 


•1637 


.1725 


4i 


.2222 


.1526 


.0744 


.0689 


.IIII 


.0707 


.GUI 


.1478 


•1533 


5 


.2 


•1373 


.0670 


.0620 


.1000 


.0637 


.0100 


'^330 


.138 


6 


.1666 


.1144 


.o55« 


•0517 


.0833 


•0531 


.0083 


.1108 


.115 


7 


.1428 


.0981 


.0479 


.0443 


.0714 


•04S5 


.0071 


•095 


.0985 


8 


.125 


.0858 


.0419 


.0388 


.0625 


.0398 


.0062 


.0818 


.0862 


9 


.iiii 


.0763 


.0372 


•0344 


.0555 


•0354 


•0055 


.0739 


.0766 


10 


.10 


.0687 


•0335 


.0310 


.0500 


.0318 


.005 


.0665 


.069 


12 


.0833 


.0572 


.0279 


.0258 


.0416 


.0265 


.0042 


•0551 


.0575 


16 


.0625 


.0429 


.0209 


.0194 


.0312 


.0199 


.0031 


.0409 


.0431 


20 

r 


.050 


•0343 


.0167 


.0155 


.0250 


.0159 


.0025 


.0332 


.0345 



WORM WHEEL HOBS 



41 



WORM WHEEL HOBS 

Hobs are made larger in diameter than the worm they are used 
with by the amount of two clearances. The Brown & Sharpe method 
is to make the clearance one-tenth of the thickness of the tooth on 
the pitch line or .05 inch for a worm of one pitch. If the worm was 
3 inches oulside diameter, which would be a fair proportion for this 
pitch, the outside diameter of the hob would be 3 + (2 X .05) = 3.1 
inches. The thread tool would be .31 inch wide at the point and 
would cut .6366 -f .1 = .7366 deep, leaving the top of the thread 
the same thickness as the bottom, which is different from the worm. 

The land L should be made as near the proportions given as pos- 
sible. 




A = .G9xPitch 
B = .3Ix Pitch. 
C = VlO ofT 
£ = .C9xPitch=A 
J = .3683xPitcn 



S=.368SxKtch 
T = .5 X Pitch 
~W=.31 X Ktch=I 
■W.D=.7366x.Htcli 




D =Diam. of Worm + ! 
L = WD + i^inoh 
WD=.7366xHteh 



Fig. 18. — Section of Hob Thread Fig. 19. — End View of Hob 



The diagram Fig. 18 shows the shape and proportions of the thread 
of a worm hob, and Fig. 19 shows the proportions for the depth of 
tooth, the lead and the oulside diameter. In these diagrams: 

A = Width of space at top of tooth. 
B = Width of thread at top. 

C = Clearance or difference between the hob and worm. 
D = Diameter of hob. 
E = Width of tooth at bottom. 
F = Hight above pitch line; 
L = Width of land or tooth at bottom. 
'S' = Depth below pitch line. 
T = Width at pitch line. 
W = Width of space at bottom. 
WD = Whole depth of tooth. 

Brown & Sharpe allow clearance at the point of the tooth only 
lor worm wheels, but at both point and bottom when bobbing 
spur gears. 



PIPE AND PIPE THREADS 



BRIGGS STANDARD PIPE THREADS 

The particulars in the following paragraph regarding this system 
of pipe standards are from a paper by the late Robert Briggs, C.E., 
read in 18S2, before the Institution of Civil Engineers of Great 
Britain. 

The taper employed has an inclination to i in 32 to the axis. The 
thread employed has an angle of 60 degrees; it is slightly rounded 
off, both at the top and at the bottom, so that the hight or depth of 
the thread, instead of being exactly equal to the pitch X .866 is 

only four-fifths of the pitch, or equal to 0.8 , ii n be the number of 



i<2 in 1 of Length 



Perfect Thread Top and 
Bottom = (0.8 Dia.+4.8) 3 



Taper of Pipe End -% per Ft.=^g per In, 

Depth of Thread ( E ) = — 

ThJ. per In. 

li=Number of Threads per In. 

Fig. 1. — Longitudinal Section of Briggs Pipe Thread 

threads per inch. For the length of tube-end throughout which 
the screw-thread continues perfect, the formula used is (o.S D 4- 4.8) 

X -, where D is the actual external diameter of the tube throughout 
11 

its parallel length, and is expressed in inches. Further back, be- 
yond the perfect threads, come two having the same taper at the 
bottom, but imperfect at the top. The remaining imperfect portion 
of the screw-thread, furthest back from the extremity of the tube, 
is not essential in any way to this system of joint; and its imperfec- 
tion is simply incidental to the process of cutting the thread at a 
single operation. 

Thread Section 

The threads as produced at the pipe end in the Briggs system 
are represented clearly in the longitudinal section. Fig. i. 

Here the threads that are perfect at top and bottom are shown 
at F, the depth being indicated at E. Back of the perfect threads 

42 



BRIGGS STANDARD PIPE THREADS 



43 



are represented the two threads with perfect bottom and flat tops 
and behind these are the imperfect threads produced by the chamfer 
or bell mouth of the threading die. A table giving the general 
dimensions of wrought iron tubes in the Briggs system will be found 
on page 40, while complete data pertaining to the thread depths, 
lengths of perfect and imperfect portions, allowances for making the 
joint in screwing the pipe into the fitting, gaging allowances, etc., 
are contained in the tables on pages 47 and 4g. 

In cutting pipe threads with a lathe tool as in threading taper 
work in general, the tool should be set at right angles to the axis 
of the piece and not square with the conical surface. 



Standard Dimensions of Wrought-Iron Welded Tubes 
Briggs Standard 



Diameter of Tubes 




Screwed Ends 






Thickness 

of Metal 

Inches 






Nominal 
Inside 


Actual 
Inside 


Actual 
Outside 


Number of 
Threads 


Length of 
Perfect 
Thread 
Inches 


Inches 


Inches 


Inches 




per Inch 


: . 


0.270 


0.405 


0.068 


27 


0.19 


■ ■ 


0.364 


0.540 


0.088 


18 


0.29 


f 


0.494 


0.675 


0.091 


18 


0.30 


J 


0.623 


0.840 


0.109 


14 


0-39 


f 


0.824 


1.050 


0.113 


14 


0.40 


1 


1.048 


I.315 


0.134 


III 


0.51 


i| 


1.380 


1.660 


0.140 


Hi 


0.54 


li 


I.610 


1.900 


0.145 


Hi 


0-5S 


2 


2.067 


2-375 


0.154 


Hi 


0.58 


2| 


2.468 


2.875 


0.204 


8 


0.89 


3 


3.067 


3-500 


0.217 


8 


0.95 


3i 


3-548 


4.000 


0.226 


8 


1. 00 


4 


4.026 


4.500 


0.237 


8 


1.05 


4l 


4.508 


5.000 


0.246 


8 


1. 10 


5 


5-f545 


5-563 


0.259 


8 


1. 16 


6 


6.065 


6.625 


■ 0.280 


8 


1.26 


7 


7.023 


7.625 


0.301 


8 


1.36 


8 


7.982 


8.625 


0.322 


8 


1.46 


♦9 


9.000 


9.688 


0-344 


8 


1-57 


10 


10.019 


10.750 


0.366 


8 


1.68 



* By the action of the manufacturers of wrought-iron pipe and 
boiler tubes, at a meeting held in New York, May 9, 1889, a change 
in size of actual outside diameter of 9-inch pipe was adopted, mak- 
ing the latter 9.625 instead of 9.688 inches, as given in the table of 
Briggs standard pipe diameters. 



44 



PIPE THREADS 



The table below shows the British pipe and pipe threads, sizes 
recommended by the Engineering Standards Committee. 

BRITISH STANDARD PIPE THREADS 











i-( 


-d 


Distance 01 


Gage 


1- 




s 


5 '- 


(-T-d 


J 


-^ jj 


t 


Dl-vmeter 


FROM 


<u 


a3 


1 


O ij 


_jj rt 


^x. 


i»s 


J3 - 


End of Pipe 


11^ 




•2S. 


Hi 


ll 


D C3 
0-^ 


■IP 


•0^ 










OS 








Q^o 


g'o 


O 4J o 




3^ 

3*^ 


1^1 


n 


1 


it 

^6 




le^^ 


.-H- 


1 







r 


i 


en 


|"o« 




•|^W 


i 


hi 


0.383 


0.046 


0.337 


28 


3% 


0.18 


0.13 


0.373 


0.327 


I 


hi 


0.518 


0.067 


0.451 


19 


1^6 


0.22 


0.16 


0.506 


0.439 


t 


i^ 


0.656 


0.067 


0.589 


19 




0.29 


0.21 


0.640 


0.573 


§ 


§1 


0.825 


0.091 


0.734 






0.29 


0.21 


0.809 


0.718 


f 


ie 


0.902 


0.091 


0.811 






0.29 


0.21 


0.886 


0-795 


f 


ii'.- 


1. 041 


0.091 


0.950 






0.44 


0.31 


1.018 


0.927 


1 


13^2 


1. 189 


0.091 


1.098 






0.44 


0.31 


1. 166 


1.075 


I 


n\ 


1.309 


0.116 


1. 193 






0.44 


0.31 


1.286 


1. 170 


li 


lu 


1.650 


0.116 


1-534 






0.58 


0.42 


1. 619 


1-503 


i§ 


iSi 


1.882 


0.116 


1.766 






0.58 


0.42 


1.851 


1-735 


If 


23% 


2. 116 


0.116 


2.000 






0.73 


0.52 


2.077 


1. 961 


2 


2| 


2.347 


0.116 


2.231 






0.73 


0.52 


2.308 


2.192 


2i 


2| 


2.587 


0.116 


2.471 






0.80 


0.57 


2.544 


2.801 


2i 


3 


2.960 


0.116 


2.844 






0.80 


O.S7 


2.917 


3-043 


2f 


3i 


3.210 


0.116 


3.094 






0.95 


0.68 


3-159 


3-293 


3 


3l 


3.460 


0.116 


3-344 






0-95 


0.68 


3-409 


3.293 


3i 


3f 


3.700 


0.116 


3-584 






1.02 


0-73 


3-645 


3-529 


• 3i 


4 


3.950 


0.116 


3.834 






1.02 


3-73 


3.895 


3-779 


3f 


4i 


4.200 


0.116 


4.084 






1.02 


0.73 


4-145 


4.029 


4 


4l 


4.450 


0.116 


4-334 






1. 17 


0.83 


4-387 


4.271 


4§ 


5 


4-950 


0.116 


4-834 






1. 17 


"0.83 


4-887 


4-771 


5 


5^ 


5.450 


0.116 


5-334 






I-3I 


0.94 


5-380 


5.264 


5^ 


6 


5.950 


0.116 


5.834 






1.46 


1.04 


s-872 


5-756 


6 


6f 


6.450 


0.116 


6.334 






1.60 


115 


6.364 


6.248 


7 


7§ 


7.450 


0.128 


7.322 






1.60 


I-15 


7-364 


7.236 


8 


8i 


8.450 


0.128 


8.322 






1-75 


1-25 


8.356 


8.228 


Q 


9l 


9-450 


0.128 


9.322 






1-75 


1.25 


9-356 


9.228 


lO 


loi 


10.450 


0.128 


10.322 


10 




1.90 


1-35 


10.348 


10.220 


II 


II i 


11.450 


0.160 


11.290 


8 




1.90 


1.35 


11.348 


II. 188 


12 


12 § 


12.450 


0.160 


12.290 


8 




1.90 


1-35 


12.348 


12.188 


13 


13 f 


13.680 


0.160 


13.520 


8 




1.90 


1-35 


13-578 


13-418 


14 


14 f 


14.680 


0.160 


14-520 


8 


if 


2.04 


1.46 


14.571 


14.411 


15 


15 f 


15.680 


0.160 


15-520 


8 


I - 


2.04 


1.46 


15-571 


15-411 


i6 


i6i 


16.680 


0.160 


16.520 


8 


If 


2.19 


1.56- 


16.563 


16.403 


17 


17 f 


17.680 


0.160 


17.520 


8 


2 


2.33 


1.67 


17.555 


17-395 


i8 


i8f 


18.680 


0.160 


18.520 


8 


2 


..33 


.6, 


18.555 


18.395 




Paper o 


; pipe end 


S = l^e" 


to l". 


W 


tiitwc 


rth stai 


idard tl 


ireads. 





TAP DRILLS FOR PIPE TAPS 



45 



Tap Drills for Pipe Taps 

The sizes of Twist Drills to be used in boring holes, to be reamed 
with Pipe Reamers, and Threaded with Pipe Taps, are as follows: 



Size 
Pipe 
Tap 


BRIGGS 


WHITWORTH 


Size 
Pipe 
Tap 


BRIGGS 


WHITWORTH 


Thread 


Drill 


Thread 


Drill 


Thread 


Drill 


Thread 


Drill 


i 


27 


U 


28 


A 


If 








iH 


1 
i 


i8 


u 


19 


II 


2 


III 


2t\ 




2^\ 


1 


i8 


T% 


19 


^ 


2i 








2H 


i 


14 


H 


14 


H 


2i 


8 


2t\ 




2|| 


1 






14 


If 


2f 








3 


f 


14 


II 


. 14 


II 


3 


8 


3t6 




3l 


I 






14 


ItV 


3i 








3i 


I 


iii 


li 


II 


li 


3h 


8 


3H 




3f 


li 


11^ 


iM 


II 


iM 


3f 








4 


I^ 


Hi 


Iff 


II 


III 


4 


8 


4A 




4i 



Metric Pipe Threads 



Nominal Inside 

Pipe Diameter 

in Inches 


Inside Pipe 
Diarneter in 
Millimeters 


External Thfead 
Diameter in 
Millimeters 


Internal Thread 
Diameter in 
Millimeters 


Number of 
Threads 
per Inch 


i 




10 


8.3 


19 


i 


6-35 


13 


II-3 


19 


f 


9.52 


16.5 


14.8 


19 


^ 


12.70 


20.5 


18.2 


14 


1 


15-87 


23 


20.7 




f 


19.05 


26.5 


24.2 




I 


25.40 


33 


30 




i| 


31-75 


42 


39 




li 


38.10 


48 


45 




If 


44-45 


52 


49 




2 


50.30 


59-7 


56.7 




2^ 


63-50 


76 


73 




3 


76.20 


89 


86 




3^ 


88.90 


101.5 


98.5 




4 


101.60 


114 


III 





46 



PIPE THREADS 



THE PIPE JOINT IN THE BRIGGS SYSTEM 

The illustrations below and the tables on pages 43 and 44, repre- 
sent the relation of the reamer, tap, die and testing gages in the 
preparation of the Briggs pipe end and fitting preliminary to making 
up the joint. 





H^ 



Standard Ring Gage and 
Plug for Testing Fittings. 



Fig. 2. — Reamer, Tap, Die and Gages for Briggs Pipe Standard 

The illustrations to the left in Fig. 2 show the relative distances 
that the pipe reamer, tap, testing plug and pipe end are run into 
the fitting in making the joint; while at the right are shown the die 
and ring gage on the pipe end, and the relative diameters of the 
Standard ring gage and the testing plug for the fittings. 



PIPE JOINT IN THE BRIGGS SYSTEM 



47 



In pipe fitting the end of the pipe should always be cut to fit the 
Briggs standard pipe gage. The fitting should be tapped small 
in order to insure a tight joint. Theoretically the joint should be 
tight when the pipe end has been screwed into the fitting a dis- 
tance represented at H in the diagrams, Fig. 2 and following tables. 
However, to allow for errors the thread on the pipe is actually cut 
two threads beyond H. Similarly the fitting should be tapped two 
threads deeper than distance H. 

The following table used in conjunction with the illustrations 
in Fig. 2, contains information as to length and number of perfect 
and imperfect threads; distance and number of turns the pipe screws 
into fitting by hand and with wrench, or the total length and num- 
ber of threads of joint; ring and plug gage data for testing tools; 
besides general pipe dimensions, drill and reamer sizes, etc. 



Briggs Pipe Thread Table (See page 46) 



Dia. of Pipe 


Actual 
Outside 


No. of 
Threads 


Dia. at 
End of 


Dia. at 
Bottom 


Depth 
of 


Length 

of 
Perfect 
Threads 


No. of 






Perfect 


Nominal 


Actual 


per Inch 


Pipe 


of Th'd 


Thread 


Threads 


Inside 


Inside 


















A 


B 




C 


D 


E 


H 




r 


.270" 


.405" 


27 


•393" 


•334" 


.029" 


.19" 


5-13 


1." 


..364" 


.540" 


18 


.522" 


•433" 


.044" 


.29" 


5-22 


3// 


.494" 


-675" 


18 


.656" 


.568" 


.044" 


•30" 


5-4 


x» 


.623" 


.840" 


14 


.815" 


.701" 


.057" 


.39" 


5-46 


3.'f 


.824" 


1.050" 


14 


1.025" 


.911" 


.057" 


.40" 


5-6 


/" 


1.048" 


1-315" 


Hi 


1.283" 


I. I 44" 


.069" 


.51" 


5-87 


ir 


1.380" 


1.660" 


11^ 


1.626" 


1.488"- 


.069" 


.54" 


6.21 


ir 


1. 6 10" 


1 .900" 


11^ 


1.866" 


1.728" 


.069" 


.55" 


6.33 


2 " 


2.067" 


2.375" 


Hi 


2.339" 


2.201" 


.069" 


.58" 


6.67 


2Y 


2.468" 


2.875" 


8 


2.819" 


2.619" 


.100" 


.89" 


7.12 


z" 


3.067" 


3-500" 


8 


3.441" 


3.241" 


.100" 


.95" 


7-6 


3r 


3-548" 


4.000" 


8 


3-938" 


3-738" 


.100" 


1 .00" 


8.0 


4 " 


4.026" 


4.500" 


8 


4.434" 


4-234" 


.100" 


1 .05" 


8.4 


4r 


4.508" 


5. " 


8 


4-931" 


4.731" 


.100" 


1. 10" 


8.8 


5" 


5-045" 


5-563" 


8 


5-490" 


5.290" 


.100" 


1. 1 6" 


9.28 


6 " 


6.065" 


6.625" 


8 


6.546" 


6.346" 


.100" 


1.26" 


10.08 


V' 


7.023" 


7.625" 


8 


7-540" 


7-340" 


.100" 


1.36" 


10.88 


8 " 


7.982" 


8.625" 


8 


8.534" 


8.334" 


.100" 


1.46" 


11.68 


9 " 


9.000" 


9.625" 


8 


9-527" 


9.327" 


.100" 


1.57" 


12.56 


10 " 


10.019" 


10.750" 


8 


10.645" 


10.445" 


.100" 


1.68" 


13-44 



(Table Continued on Page 48) 



48 



PIPE THREADS 



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puB Sntd: 
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MHIHMMHHHHHH 


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sujnx JO -o^ 




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GAGE SETS 



49 



GAGE SETS FOR BRIGGS PIPE AND FITTINGS 

The gages manufactured by the Pratt & Whitney Company for 
makers and users of pipe and fittings include three distinct sets for 
each size of pipe, and these are illustrated in Fig. 3, Set No. i con- 
sists of a ring and plug conforming in all dimensions to the Briggs 
standard, and is known as the standard reference set. The plug 
screws into the ring wnth faces flush — as indicated by the position 
of the two gages. The flat milled on the plug shows the depth to 
which the latter should enter the fitting to allow for screwing up with 
tongs to make a steam-tight joint; the ring, of course, screws on to 
the pipe flush with the end. 




£>iT«XAW:xWA\WxW;«-.R3! 



Set No. 2 ^^=^~=^--' Set No. 3 

Working Allowance Gages. Inspection Allowance Gages. 

Fig. 3. — Briggs Pipe Thread Gages 



Set No. 2 — the working allowance set — consists of the plug 
already described and a ring whose thickness is equal to the standard 
ring less the allowance for screwing up the joint. As the plug and 
ring threads are of the same diameter at the small end, the bottom 
surfaces come flush when the two members are screwed together. 
It will be noted that, as the plug enters the fitting only to the bottom 
of the flat at the side, and the ring screws on to the pipe only far 
enough to bring the outer face flush with the pipe end, there are a 
few threads on, or in, the work beyond the reach of the gages; hence 
with this type of gage a reasonable amount of wear may be permitted 
at the end of the tap or the mouth of the die without causing the 
rejection of the work. 

The plug and ring in set No. 3 are inspection allowance gages, 
the ring being the same in all particulars as the standard gage in 
set No. I, while the plug is longer than Nos. i and 2 by an amount 
equal to the allowance for screwing up for a tight joint, this extra 
length being represented by the cylindrical portion at the rear of 



50 



PIPE THREADS 



the thread cone. When the gages are screwed together the back of 
the cylindrical section comes flush with the ring face and the threaded 
end of the plug projects through the ring, as indicated, a distance 
equal to the length of the cylinder, or the screwing-up allowance. 
This plug will enter a perfect fitting until the back of the threaded 
section is flush with the end of the fitting, thus testing the full depth 
of the tapped thread in the same way that the standard ring gage 
covers the thread on the pipe end, and at the same time showing 
that the fitting is tapped to right diameter to allow the joint to screw 
up properly. 

NATIONAL STANDARD HOSE COUPLING 

This standard' for fire hose couplings was adopted by the Na- 
tional Fire Protection Association May 26, 1905 and has since been 
approved and adopted by various other organizations. 




Fig. 4. — National Standard Hose Coupling 
Dimensions of National Standard Hose Couplings 



Inside Diameter of Hose Couplings. . . 
Length of Blank End on Male Part . . . 
Outside Diameter of Thread, Finished 

Diameter at Root of Thread 

Total Length of Male End 

Number of Threads per inch 

Length of Female Thread 

Diameter of Top of Female Thread . . 



22 


3 


3^ 


^ 






3iV 


3t 


4i 


2.871S 


3-3763 


4-0013 


I 


li 


ij 


7i 


6 


6 


8 


I 


I 


30925 


3-6550 


4.28 



4i 

i 

5l 

5-3970 

i| 

4 

li 

5-80 



Note: — The above to be of the 60-deg. V-thread pattern with one-hundredth 
inch cut off the top of thread and one-hundredth inch left in the bottom of the 2i-inch, 
3-inch, and sJ-inch couplings, and two hundredths inch in like manner for the 4j- 
inch couplings, and with one-quarter inch blank end on male part of coupling in 
each case; female ends to be cut ^-inch shorter for endwise clearance. They should 
also be bored out .03 inch larger in the 2i-inch, 3 and 3|-inch sizes, and .05 inch 
larger on the 4j-inch size in order to make up easily and without jamming or 
Sticking. 



TWIST DRILLS 

The twist-drill is perhaps one of the most efficient tools in use as, 
although one half is cut away in the flutes, it has a very large cutting 
surface in proportion to its cross-sectional area. This is made possible 
by the fact that the work helps to support the drill and the feed 
pressure on the drill tends to force the point into a cone-shaped hole 
which centers it. 

In addition to the radial relief or backing-off behind the cutting 
edge, twist -drills have longitudinal clearance by decreasing the diam- 
eter from the point toward the shank, varying from .00025 to .0015 
per inch of length. This prevents binding and is essential in accurate 
drilling. 

To increase the strength the web is increased gradually in thickness 
from the point toward the shank by drawing the cutters apart. This 
decreases chip room and to avoid this defect the spiral is increased in 
pitch and the flute widened to make up the chip room. 




PIG. I FIG. 2 FIG. 3 

Grooves of Twist Drills 

The shape of the groove affects the power and the shape of the 
chip and experiments by the Cleveland Twist-Drill Company are 
interesting. The groove in Fig. i does not give a good cutting edge, 
especially near the center, as it does not allow a full curl to the chip. 
Fig. 2 is a very free cutting-groove, the chips curl up to the full size 
of the groove and this reduces the power required to bend the cnips. 
Fig. 3 js an even better form as it rolls a chip with each turn conical 
so that one lays inside the other and makes a much shorter chip 
from the same depth of hole. 

The angle of spirals varies from 18 to 35 degrees according to the 
ideas of the maker. In theory the finer the pitch or the greater the 
angle, the easier it should be to cut and curl the chip. But this 
gives a weak cutting edge and reduces the ability to carry off the 
heat, and it does not clear itself of chips so well. After a long series 
of tests the same firm adopted 27I degrees for the spiral. This 
angle makes the spiral groove of all drills start at the point with a 
pitch equal to six diameters of the blank, the increase in twist being 
a constant function of the angular movement of rotation of the drill 
blank. This angle is based on holes from one to three diameters 
deep. For deeper holes a smaller angle might be advisable and 
greater angle for holes of less depth. There is practically no differ- 
ence in torsional stress with the angle between 25 and 30 degrees. 

SI 



52 



TWIST DRILLS 



Sharpening Drills 

Drills should be sharpened so as to cut the right size and with as 
little power as possible. To cut the right size both lips must be the 
same length and the same angle. A gage as shown in Fig, 4 will 
help both to get the angle and to grind them central. This gives the 
usual lip edge of 59 degrees. Fig. 5 shows how you can see if both 
lips are ground alike, but does not give the angle. Fig. 6 is a sug- 
gestion by Professor Sweet of relieving the drill back of the cutting 
edge, making it similar to a flat drill in this respect. 

For drilling brass or for any thin stock where the drill goes clear 
through, it is best to grind the cutting edge parallel with the axis of 




FIG. 9 



FIG. 6 



Grinding Twist Drills 



the drill. This does away with the tendency to draw into the work. 
Fig. 7 shows how this is done. 

It is sometimes necessary to thin the point of the drill to get best 
results. This requires care in grinding but can be done as shown 
in Fig. 8. 

The best all-around clearance angle is 12 degrees, though for 
softer metals 15 degrees can be used. The 12 degrees is the angle 
at the cutting edge, but this should increase back of the cutting edge 
so that the line across the web should be 45 degrees, with the cutting 
edges. This is important, as it not only saves power but prevents 
splitting in hard service. The point of the drill should look like 
Fig. 7 or Fig. 8. Fig. 9 shows the clearance angle and the right 
angles for the drill point. 



SPEEDS AND FEEDS 



S3 



Speed of Drills 

Learn to run drills at their proper speed to secure the most work 
with fewest grindings and breakages. The best practise is to use a 
speed that will give 30 feet a minute cutting speed for steel, 35 feet 
for cast iron and 60 feet for brass. This means that the cutting edge 
must run fast enough to make these speeds. For drilling steel with 
a xV-inch drill this means 1834 revolutions a minute, while for brass 
it would be 3668 revolutions. The table gives the speeds without 
any figuring for all drills up to 3- inches. These speeds require 
plenty of lubricant. This is for carbon steel drills. 

These speeds can be exceeded in many cases even with carbon drills, 
and can be doubled with high speed drills, in fact from 75 to 150 feet 
is not uncommon with 200 feet a possibility under good conditions. 
The feeds in the table below can also be doubled in many cases. 

Table of Drill Feeds 



7=i 




Inches of Feed per Minute at Cutting Speed of 






2 
"0 


30 Feet-Steel 


35 Feet-Iron 


60 Feet-Brass 


E 
Q 


Rev. per 
Alinute 


Feed .004- 


.007 


Rev. per 
JNIinute 


.004-.007 


Rev. per 
Minute 


.004-.007 

per Revolution 


T^^ 


1834 


7-33 


12.83 


2140 


8.56 


14.97 


3668 


14.66 


25.76 


i 


917 


3.66 


6.41 


1070 


4.28 


7^49 


1834 


7^33 


12.83 


1% 


611 


2.44 


4.27 


713 


2.85 


4.99 


1222 


4.88 


8.58 


i 


458 
367 


1.83 


3.20 


535 


2.14 


3^74 


917 


3.66 


6.44 




Feed .007 


.015 




.007 


.015 




.007 


.015 


T% 


2-57 


5-5 


428 


S 


6.42 


733 


5-14 


II 


1 


S06 


2.14 


4.6 


357 


2.5 


5^35 


611 


4.28 


9.2 


t\ 


262 


1.83 


3-9 


306 


2.14 


4^58 


524 


3.66 


7^8 


h 


229 


1.60 


3-43 


268 


1.87 


4- 


459 


3.20 


6.86 


* 


184 


1.28 


2-75 


214 


1.50 


3.21 


367 


2.57 


5-5 


f 


153 


1.07 


2.3 


178 


1.25 


2.67 


306 


2.14 


4.6 


i 


131 


.91 


1-95 


153 


1.07 


2.29 


262 


1.88 


3-93 


I 


115 


.80 


1. 71 


134 


.93 


2 


229 


1.60 


3-43 


I^ 


102 


•71 


i-';3 


119 


•83 


1.79 


204 


1-43 


3.06 


li 


91.8 


.64 


1-37 


107 


•75 


1.61 


183 


1.28 


2.7s 


if 


83.3 


•58 


1.25 


97.2 


.68 


1-45 


167 


1. 17 


2.51 


li 


76.3 


•53 


I-I5 


89.2 


.62 


1^38 


153 


1.07 


2.3 


I^ 


70-5 


.49 


1. 05 


82.2 


.57 


1.23 


141 


•99 


2. IT 


I^ 


65-5 


.45 


•97 


76.4 


.53 


I-I5 


131 


•94 


1.90 


I^ 


61. 1 


.42 


.92 


71-3 


•50 


1.07 


122 


•85 


I.81 


2 


57-3 


.40 


.85 


66.9 


.46 


I. 


115 


.80 


1-73 


2\ 


51 


.36 


•71 


59-4 


.41 


•89 


102 


•71 


1-53 


2h 


4S.8 


•32 


.68 


53-5 


•37 


.80 


91.7 


.64 


1-37 


n 


41.7 


.29 


.62 


48.6 


•34 


•73 


83.4 


•58 


1. 21 


3 


38.2 


.27 


•57 


44.6 


•31 


•^1 


7^-4 


•53 i^i5 



54 



TWIST DRILLS 



Feed of Drills 

The feed of drills is usually given in parts of an inch per revolution, 
0.004 to 0.007 irich for drills of J inch and smaller and 0.007 to 0.015 
inch for larger drills being recommended. This has been worked 
out into the table for the standard speeds to show inches of feed per 
minute for the three speeds given, which is more convenient. This 
is not an iron-clad rule but should be used with judgment. For 
high-speed steel these figures can be just about doubled. 



Data for Drilling Cast Iron at Feed of \" per Min. 









H.P. for 








H.P. for 


Size of 


Feed per 


Thrust in 


I Inch 


Size of 


Feed per 


Thrust in 


I Inch 


Drill 


Rev. 


Lbs. 


Feed per 
Min. 


Drill 


Rev. 


Lbs. 


Feed per 
Min. 


I 


.02 


1300 


•0035 




.06 


8000 


.02 




.04 


2600 


.0063 


2h 


.02 


3200 


.008 




.06 


3900 


.010 




.04 


6500 


.016 


li 


.02 


2000 


.005 




.06 


9700 


.024 




.04 


3900 


.010 


3 


.02 


3750 


.009 




.06 


5800 


.015 




.04 


7700 


.019 


2 


.02 
.04 


2500 
5300 


.006 
.013 




.06 


1 1 500 


.029 



For carbon steel the values run from i Ho 3 times these for cast 
iron, increasing with the feed per revolution. 

One inch flat twisted drills have been run from 313 to 575 r. p. m., 
with feeds of 11.27 and 28.1 inches per minute and required from 5.22 
to 11.60 actual horse power. 



Torque Required to Drill Cast Iron 



Diam. of 


Feed in 

Inch 
per Rev. 


Pounds 
Torque 
at I foot 
Radius 


H.P. per 


Diam of 


Feed in 

Inch 
per Rev. 


Pounds 
Torque 


H.P. per 


DriU 


Rev. 


Drill 


at I foot 
Radius 


Rev. 


I 


.02 


50 


.009 




.06 


390 


.072 




.04 


80 


.014 


A 


.02 


200 


.038 




.06 


120 


.023 




.04 


400 


.076 


i^ 


.02 


75 


.014 




.06 


600 


.114 




.04 


150 


.028 


3 


.02 


280 


•053 




.06 


225 


.042 




.04 


575 


.109 


2 


.02 
.04 


125 
25s 


.023 
.048 




.06 


870 


.167 



DRILL POINTERS $5 



Drill Troubles 

Twist-drills will stand more strain in proportion to their size and 
weight than almost any other tool, and when a good drill gives trouble 
it is pretty safe to say some of the conditions are wrong. 

If it chips on the edge, the lip clearance is too great and fails to 
support the cutting edge or the feed is too heavy. Ease off on the 
feed first and then watch the grinding. 

If it splits in the web it is either ground wrong, i.e., does not have 
the center lip at the angle of 45 degrees or the feed is altogether too 
heavy. 

If the outer corner wears, it shows that the speed is too great. 
This is pardcularly noticeable on cast iron. 

Drill Pointers 

In most cases it is better to use high speeds almost to the point 
where the drill corners commence to wear with a light feed than to 
use slower speed and heavy feed. 

This is specially true of drilling in automatic machines where the 
holes are not more than twice as deep as the diameter where drills 
are flooded vat\\ lard oil. With deeper holes the chips are harder to 
get rid of and it is better to use slower speeds and heavier feeds as 
the drilled hole gets deeper. Speeds of 10,000 r, p. m. for drills i^in. 
and smaller are not uncommon. 

Watch the drill chip and try to grind so that it will come out in a 
small compact roll. It is better to have this continuous clear to 
bottom of hole if possible. 

In drilling brass use a heavier feed especially on automatic ma- 
chines, as it helps to work out the chips. If you lubricate at aU, 
flood the work. Twist-drills ground as for steel often catch and 
"hog in" on brass, especially at the bottom of the hole, where it 
breaks through. To avoid this, grind the lead or rake from the 
cutting edge. 

In drilhng hard material use turpentine as a lubricant. 

Drills feed easier by thinning the extreme point if this is carefully 
done. This is important in hand feeding. 

High-speed drills work best when warm. Lubricant should be 
heated to 150 degrees F. when starting drills to work; they will soon 
maintain the proper temperature. 

Special Drills and Their Uses 

Ratchet-drills have a square taper shank, are used in hand-ratchet 
braces and in air-driven drills. Used in bridge building, structural 
and repair work. 

The shell drill, Fig. 10, is used after a two-groove drill in chucking 
out cored holes or for enlarging holes that have been made with a 
two-groove drill. It has a taper hole and a number of sizes can be 
used on the same arbor. 



56 TWIST DRILLS 

Wire drills and jobbers or machinists drills both have round shanks 
and only differ in size. Wire drills are made to a twist-drill gage and 
the others to a jobbers or fractional gage. 

Blacksmith drills all have a ^-inch shank 2j inches long, so as to 
all fit the same holder. There is a flat on the shank for set-screw. 

The straightway or Farmers drill has the same clearance as a 
twist-drill but the flutes are straight. It is used mostly in drilling 
brass and soft metals or in drilling cross holes or castings where blow 
holes may be found, as it is less likely to run than the twist -drill. 

Oil drills have the advantage of the cutting edge being kept cool 
and of the chips being forced back through the grooves which reduces 
friction to a minimum. They are used for all kinds of drilling, 
mostly deep hole work. In cast-iron drilling air is sometimes used 
to blow out the chips and keep the drill cool. They are generally 
used in a screw or chucking machine or a lathe fitted for this work. 
Where the drill is held stationary and the work revolves, the oil 
is pumped to the connection and flows through the holes in the drill 
as in Fig. ii. 

Where the drill revolves 
as in a drill press, the oil 
is pumped into a collar 
which remains stationary 
while the drill socket re- 
volves, as in Fig. 12. An 
oil groove around the 
socket and holes through 
to the drill connects with 
the holes in the drill it- 
self. Other types are 
shown in Figs. 13 and 14. Fig. 10. ■ — Shell Drill 

The latter is used mostly 

in screw or chucking machine turrets where the oil is pumped into 
the center of the turret and into the large hole in the shank of the drill. 

The hollow drill shown in Fig. 15 is used for deep drilling or long 
holes and is used in a lathe or some similar machine fitted for the 
purpose. It has a hole lengthwise through the shank connecting 
with the grooves of the drill. The shank can be threaded and fitted 
to a metal tube of such length as desired. The outside of the drill 
has a groove the whole length of the body. The lubricant is con- 
veyed to the point of the drill on the outside through these grooves, 
while the hollow tube admits of the passage of oil and chips from 
the point. In using this drill the hole is first started with a short 
drill the size of the hole desired and drilled to a depth equal to the 
length of the body of the hollow drill to be used. The body of the 
hollow drill acts as a packing, compelling the oil to follow the grooves 
and the chips to flow out through the hollow shank. 

Three and four groove drills are used for chucking out cored holes 
or enlarged holes that are first drilled with a two-groove drill. They 
are much better than a two-groove drill for use in cored holes or to 
follow another drill. The ends of the drills, Fig. 16 and 17, indicate 
that they are not made to drill from solid stock but for enlarging a 
hole already made- 




TYPES OF DRILLS 



57 




Q 



cn^B 



FIG. II 



FIG. 12 



FIG. 13 



FIG. 14 



FIG. 15 



FIG. 16 



Q 






FIG. 17 



58 



TWIST DRILLS 



The following tables give standard drill sizes in various ways, each 
being very convenient for certain classes of work: 



Decimal Equivalents of Nominal Sizes of Drills 









'*:' 








i . 














u 


_ 






m 









w 


"o 






tc 


mJ^ 






M 


tr.J^ 






£0 


U3^ 






a 


-- u 






rt 



















i^ 









1^ 









1- 


1 


S 
^ 








<, 
^ 


a 
^ 




J3 






'0 ^ 






80 


•0135 




1.2 




.047244 






37 


,104 






79 


.0145 




1-3 




.051181 




2.7 




.1063 


i^ 






,015625 






55 


.052 






2,(> 


.1065 




.4 




.01574 






54 


.055 ^ 


-e\ 






.109375 






78 


.016 




1.4 




.055118 






35 


.11 






77 


.018 




1-5 




.05905 




2.8 




.11024 




•5 




,01968 






53 


•0595 






34 


.III 






76 


.020 


r^. 






.0625 






33 


.113 






75 


.021 




1.6 




.06299 




2.9 




.11417 






74 


.0225 






52 


•0635 






32 


.116 




.6 




.02362 




1-7 




.066929 




3 




.II8II 






73 


.024 






51 


.067 






31 


.12 






72 


.025 






50 


.07 




3^1 




.12205 






71 


.026 




1.8 




.070866 


\ 






.125 




.7 




.02756 






49 


•073 




3-2 




.12598 






70 


.028 




1.9 




.0748 






30 


.1285 






69 


.02925 






48 


.076 




3-3 




.12992 






68 


.031 


e\ 






.078125 




3-4 




.13386 


■s\ 






•03125 






47 


.0785 






29 


.136 




.8 




.031496 




2 




.07874 




3-5 




.1378 






67 


.032 






46 


.081 






28 


.1405 






66 


.033 






45 


.082 


^\ 






.140625 






65 


.035 




2.1 




.082677 




3^6 




.14173 




•9 




.03543 






44 


.086 






27 


.144 






64 


.036 




2.2 




.086614 




3-7 




.14567 






63 


.037 






43 


.089 






26 


.147 






62 


.038 




2-3 




•09055 






25 


•1495 






61 


.039 






42 


.0935 




3-8 




.14961 




I 




.03937 


-h 






'O9375 






24 


.152 






60 


.04 




2.4 




.09448 




3-9 




.15354 






59 


.041 






41 


.096 






23 


.154 






58 


.042 






40 


.098 


z\ 






.15625 






57 


.043 




2.5 




.098425 






22 


.157 




I.I 




.043307 






39 


•0995 




4 




.15748 






56 


.0465 






38 


,1015 






21 


•159 


e\ 






.046875 




2.6 




.102362 






20 


.161 



SIZES OF DRILLS 59 

Decimal Equivalents of Nominal Sizes of Drills, Continued 







« 


•0 






ej 


"0 






^ 


•o 






M 


tn-£3 






N 


t«-d 






N 


,/i jd 









1^ 






-in 








U 


|l 








Q 




^ 


1 


■•gl 


a 


s 
^ 


V 

3 


"0 
Q 




4.1 




.16142 






A 


.234 






p 


•323 




4.2 




•16536 


M 






•234375 


H 






.328125 






19 


.166 




6 




.23622 






Q 


•332 




4-3 




.16929 






B 


.238 




8.5 




•33465 






18 


.1695 




6.1 




.24015 




8.6 




•33859 


l\ 






•171875 






C 


.242 






R 


•339 






17 


•173 




6.2 




.2441 


M 






•34375 




4.4 




•17323 






D 


.246 




8.8 




.34646 






16 


.177 




6.3 




.24803 






S 


.348 




4.5 




.17717 


i- 




E 


•25 




9 




•35433 






15 


.18 




6.4 




.25197 






T 


•358 




4.6 




.1811 




6.5 




•25591 


If 






•359375 






14 


.182 






F 


•257 




9.2 




.36221 






13 


.185 




6.6 




.25984 






U 


.368 




4-7 




.18504 






G 


.261 




9^5 




.37402 


T% 






•1875 




6.7 




.26377 


1 






•375 




4.8 




.18898 


H 






.265625 






V 


•377 






12 


.189 






H 


.266 




9.6 




•37796 






II 


.191 




6.8 




.26772 




9.8 




•38583 




4.9 




.19291 




6.9 




.27165 






w 


•386 






10 


•1935 






I 


.272 


If 






.390625 






9 


.196 




7 




•27559 




10 




•3937 




5 




.19685 






J 


.277 






X 


•397 






8 


.199 




7^1 




.27952 






Y 


•404 




5.1 




.20079 






K 


.281 


M 






.40625 






7 


.201 


3^2 






.28125 






Z 


■413 


if 






.203125 




7.2 




•28347 




10.5 




•4134 






6 


.204 




7-3 




.2874 


II 






•421875 




5-2 




.20473 






L 


•29 




11 




•43307 






5 


•2055 




7-4 




•29133 


tV 






•4375 




5-3 




.20866 






M 


•295 ^ 




"•5 




•45276 






4 


.209 




7^5 




.29528 


II 






•453125 




5-4 




.2126 


M 






.296875 


M 






•46875 






3 


.213 




7.6 




.29922 




12 




.47244 




5-5 




.21654 






N 


.302 


fi 






•484375 


z\ 






.21875 




7^7 




•30314 




12.5 




.4921 




5-6 


2 


.22047 
.221 




7.8 
7^9 




.30709 
.31102 


i 






•5 




5-7 


I 


.22441 
.228 


A 


8. 




•3125 
.31496 












5-8 




.22835 









.316 












5-9 




.23228 




8.2 




.32284 











6o TWIST DRILLS 

Decimal Equivalents of Nominal Sizes of Drills, Continued 







1^ 














05 -fl 
























rt a 






2 fl 






rt a 






E^ 






E^ 








-d 


s 


•g^ 


^ 


s 


"C c 


-s 


s 


c 




^' 


Q 




^ 


Q 




^ 


Q 




13 


.51181 


n 




.671875 


n 




.84375 


ff 




.515625 


H 




.6875 




21-5 


.84646 


if 




.53125 




17-5 


.689 


M 




•85937s 




13-5 


.5315 


i^ 




.703125 




22 


.86614 


f* 




.546875 




18 


.70866 


i 




.875 




14 


•55118 


M 




.71875 




22.5 


•88583 


T% 




.5625 




18.5 


.72835 


n 




.890625 




14-5 


.57087 


n 




.734375 




23 


.90551 


n 




.578125 




19 


.74803 


^ 




.90625 




15 


.59055 


f 




.75 . 


H 




.921875 


F 




.59375 


n 




.765625 




23-5 


.9252 


M 




•609375 




19-5 


.76772 


It 




•9375 




15-5 


.61024 


B 




.78125 




24 


.94488 


t 




.625 




20 


.7874 


U 




.953125 




16 


.62992 


H 




.796875 




24-5 


.9646 


U 




.640625 




20.5 


.8071 


U 




.96875 




16.5 


.6496 


n 




.8125 




25 


•98425 


u 




.65625 




21 


.82677 


n 




.984375 




17 


.66929 


n 




.828125 


I 




I. 



Letter Sizes of Drills 



Diameter 


Decimals 


Diameter 


Decimals 


Inches 


of I Inch 


Inches 


of I Inch 


A H 


.234 


N 


.302 


B 


. .238 


A 


.316 


C 


.242 


P Ik 


•323 


D 


.246 


Q 


•332 


E i 


•250 


RM 


•339 


F 


.257 


s 


•348 


G 


.261 


Tff 


.358 


H il 


.266 


U 


.368 


I 


.272 


Vf 


.377 


■ 


•277 


Wfl 


.386 


K j\ 


.281 


X 


.397 


L 


.290 


YM 


.404 


Mil 


.295 


z 


.413 



SIZES OF DRILLS 



6i 



Decimal Equivalents of Drill Sizes from ^ to No. 8o 



Size 


Decimal 


Size 


Decimal 


Size 


Decimal 


Equivalent 


Equivalent 


Equivalent 


3^1 


0.500 


3 


0.213 


iV 


0.0937 




0.4843 


4 


0.209 


42 


0.0935 


it 


0.4687 


5 


0.2055 


43 


0.089 


If 


0.4531 


6 


0.204 


44 


0.086 


t\ 


0-4375 


if 


0.2031 


45 


0.082 


n 


0.4218 


7 


0.201 


46 


0.081 


z 


0.413 


8 


0.199 


47 


0.0785 


M 


0.4062 


9 


0.196 


/t 


0.0781 


Y 


0.404 


10 


0.1935 


48 


0.076 


X 


0-397 


II 


O.191 


49 


0.073 


If 


0.3906 


12 


0.189 


50 


0.070 


W 


0.386 


t\ 


0.1875 


51 


0.067 


V 


0.377 


13 


0.185 


52 


0.0635 


1 


0.375 


14 


0.182 


tV 


0.0625 


u 


0.368 


15 


0.180 


53 


0.0595 


If 


0.3593 


16 


0.177 


54 


0.055 


T 


0.358 


17 


0.173 


55 


0.052 


s 


0.348 


ii 


O.1718 


e\ 


0.0468 


# 


0.3437 


18 


0.1695 


56 


0.0465 


R 


0.339 


19 


0.166 


57 


0.043 


Q 


0.332 


20 


O.161 


58 


0.042 


H 


0.3281 


21 


0.159 


59 


0.041 


p 


0.323 


22 


0.157 


60 


0.040 


o 


0.316 


A 


0.1562 


61 


0.039 


A 


0.3125 


23 


0.154 


62 


0.038 


N 


0.302 


24 


0.152 


63 


0.037 


if 


0.2968 


25 


0.1495 


64 


0.036 


M 


0.295 


26 


0.147 


65 


0.035 


L 


0.290 


27 


0.144 


66 


0.033 


i\ 


0.2812 


e\ 


0.1406 


s\ 


0.0312 


K 


0.281 


28 


0.1405 


67 


0.032 


J 


0.277 


29 


. 0.136 


68 


0.031 


I 


0.272 


30 


0.1285 


69 


0.029 


H 


0.266 


i 


0.125 


70 


0.028 


if 


0.2656 


31 


0.120 


71 


0.026 


G 


0.261 


32 


O.I 16 


72 


0.025 


F 


0.257 


33 


O.I 13 


73 


0.024 


E-i 


0.250 


34 


O.I II 


74 


0.0225 


D 


0.246 


35 


O.IIO 


75 


0.021 


C 


0.242 


6^ 


0.1093 


76 


0.020 


B 


0.238 


36 


0.1065 


77 


0.018 


if 


0.2343 


37 


0.104 


sV 


0.0156 


A 


0.234 


38 


O.IOI5 


78 


0.016 


I 


0.228 


39 


0.0995 


79 


0.0145 


2 


0.221 


40 


0.098 


80 


0.0135 


3^ 


0.2187 


41 


0.096 







62 



TWIST DRILLS 



TAP DRILL SIZES FOR REGULAR THREADS 

These sizes give an allowance above the bottom of thread on 
sizes j%- to 2; varying respectively as follows: for "V" threads, 
.010 to .055 inch; for U. S. S. and Whitworth threads, .005 to .027 
inch. These are found by adding to the size at bottom of thread, j 
of the pitch for "V" threads, and | of the pitch for U. S. S. and Whit- 
worth, the pitch being equal to i inch divided by the number of threads 
per inch. In practice it is better to use a larger drill if the exact size 
called for cannot be had. 



Size 
Tap 


5! 


Size of Drill 


Size 
Tap 


i| 


Size of Drills 


u. s. s. 


V 


w 


U. S. S. 


V 


W 


1 

1 
•i 


24 
20 
18 
16 
14 
13 

11 
II 
II 
10 
10 
9 


.138 

.191 

.248 

.302 
.354 
.409 
.402 

.465 

.518 

.581 
.632 
.695 

• 745 


.III 
.184 
.239 

• 293 
•345 
•399 
•391 
■453 
.506 

• 568 
.618 
.680 
.728 


.129 
.192 
.249 
.303 

•355 
.410 
•403 
.466 
.520 
.583 
• 634 
•697 
•747 


if 

2'' 


9 

8 

8 

7 

7 

6 

6 

5^ 

5 

5 

li 


.808 
•854 

•917 

1.082 
1. 179 
1.304 
1. 412 
1.390 

I.5I5 

1.640 
1. 614 
1-739 


• 790 

.832 

.894 

•932 

I-OS7 

1. 144 

1.269 

1.372 

1-347 

1.472 

1^597 

1.566 

1.691 


.810 

.856 

.919 

.960 

1-085 

1. 182 

1.307 

1. 416 

1-394 

I-5I9 

1.644 

1. 619 

1.744 



A very simple rule, wliich is good enough in many cases, is: 
Subtract the pitch of one thread from the diameter of the tap. 
A f-inch tap 16- thread would be | minus jV = re drill; a f-inch 
tap, ten-thread, would be f minus i^ = yVo — t\Po or 0.75 — o.io = 
xVo or 0.65, or a little over f of an inch, so a f-inch drill will do 
nicely. With a i-inch tap we have i — | = |-inch drill, which is a 
little large but leaves enough thread for most cases. 



Tap Drills 


FOR S. A. E 


. (A. L. A 


. M.) Threads 


Size of 


Threads 


Size of Drill, 


Size of 


Threads 


Size of Drill, 


Tap 


per Inch 


Inches 


Tap 


per Inch 


Inches 


1 


28 


7 


a 


16 


*a 


i^ 


24 


Vz 


1 


14 


§§ 


f 


24 


n 




14 


II 


/s 


20 


f 




12 


leV 


h 


20 


1^^ 




12 


U\ 


I 


18 






12 


in 


f 


18 


If 




12 


in 


ih 


16 


11 









The tap should be between 0.002 and 0.003 inch large for clearance 
between top and bottom of threads. 



TAP DRILLS 



63 



TAP DRILLS 

For Machine Screw Taps 

These drills will give a thread full enough for all practical purposes 
but not a. full thread as this is very seldom required in practical work, 
Further data along this line will be found in the tables which follow. 



Tap Drills 



Sizes of 


No. of 


Sizes of 


Sizes of 


No. of 


Sizes of 


Taps 


Threads 


Drills 


Taps 


Threads 


Drills 


2 


48 


48 


12 


24 


19 


2 


56 


46 


13 


■^O 


17 


2 


64 


45 


13 


24 


15 


3 


40 


48 


14 


20 


14 


3 


48 


47 


14 


22 


13 


3 


56 


45 


14 


24 


II 


4 


32 


45 


15 


18 


12 


4 


36 


43 


15 


20 


10 


4 


40 


42 


15 


24 


7 


5 


30 


41 


16 


16 


10 


5 


32 


40 


16 


18 


7 


5 


36 


38 


16 


20 


5 


5 


40 


36 


16 


24 


I 


6 


30 


39 


17 


16 


7 


6 


32 


37 


17 


18 


4 


6 


36 


3S 


17 


20 


2 


6 


40 


33 


18 


16 


2 


7 


28 


32 


18 


18 


I 


7 


30 


31 


18 


20 


B 


7 


32 


30 


19 


16 


C 


8 


24 


31 


19 


18 


D 


8 


30 


30 


19 


20 


E 


8 


32 


29 


20 


16 


E 


9 


24 


29 


20 


18 


E 


9 


28 


27 


20 


20 


F 


9 


30 


26 


22 


16 


H 


9 


32 


24 


22 


18 


I 


10 


24 


26 


24 


14 


K 


10 


28 


24 


24 


16 


L 


10 


30 


23 


24 


18 


M 


10 


32 


21 


26 


14 





II 


24 


20 


26 


16 


P 


II 


28 


19 


28 


14 


R 


II 


30 


18 


28 


16 


S 


12 


20 


21 


30 


14 


T 


12 


22 


19 


30 


16 


U 



64 



TWIST DRILLS 



Dimensions for Twist Drills 
for boring holes to be threaded with u. s. form of thread 

TAPS jV to il INCH DIAMETER 



Diam- 


No. of 

Threads 

to the 

Inch 


Exact 
Diameter 


Gage 


Diam- 


No. of T^? 

Threads ^\ 

to the ^9^ 

Inch { 


.xact 
ameter 


Gage 


eter 


Bottom of 


No. of 


eter 


tom of 


No. of 


Inches 


Thread 
Inches 


DriU 


Inches 


hread 
nches 


DriU 


tV 


6o 


.041 


57 


1 
4 


26 


200 


6 


T> 


64 


.042 


56 


^T 


56 


055 


53 


•5" 2 


48 


.067 


50 


WV 


60 


056 


53 


A 


50 


.068 


50 


-^'^ 


40 


077 


46 


A 


56 


.071 


49 


^'^ 


44 


080 


45 


A 


60 


.072 


48 


^^ 


48 


082 


44 


i 


40 


•093 


41 


6\ 


32 


100 


38 


i 


44 


.096 


40 


/. 


36 


105 


36 


i 


48 


.098 


39 


6^T 


40 


108 


34 


^ 


32 


.116 


31 


U 


32 


131 


29 


^ 


36 


.120 


31 


U 


36 


136 


28 


3^2 


40 


.124 


30 


U 


40 


139 


28 




24 


•133 


29 


u 


24 


149 


24 


28 


.141 


27 


u 


28 


157 


21 


tV 


30 


.144 


26 


H 


32 


162 


10 


tV 


32 


.147 


25 


H 


36 


167 


18 


tV 


36 


.152 


23 




24 


I So 


13 


T^^W 


24 


.164 


19 


il 


28 


188 


10 


^V 


28 


.172 


16 


61 


32 


194 


8 


j'^ 


32 


.178 


14 


i^ 


36 


ig8 


7 


-h 


36 


.183 


12 


iT 


18 


193 


9 


i 


18 


.178 


14 


^-4 


20 


201 


5 


i 


20 


.185 


12 


h 


24 


211 


3 


i 


22 


.190 


10 


h 


26 


216 


2 


i 


24 


.196 


8 


n 


32 


225 


I 



Drills and Reamers for Dowel Pins 



Sizes of Rod 


Drills and 


Reamers for 


Drive Fits 


Drills for 


Clearance 


No. of Gage 

(Stubbs Steel 

Wire) 


Dia. 


Size of 


Dia. of 


Dia. of 


Size of 


Dia. of 


Drill 


Drill 


Reamer 


Drill 


Drill 


54 


.OSS 


No. 55 


.052 




No. 54 


•055 


45 


.081 


" 47 


.0785 




" 46 


.081 


33 


.112 


" 36 


.1065 


.110 


" 33 


•"^ 


30 


.127 


31 


.120 


.125 


" 30 


.1285 


21 


.157 


" 24 


.152 


•155 


22 


•157 


10 


.191 


" 13 


.185 


.189 


" II 


.191 




.2S2 


c 


.242 


.250 -.2505 


F 


.257 




•315 


■is Reamer 
Drill 


.307 


■3r25-.3i3 





.316 


V 


.377 


1 


' 


.366 


■375 --3755 


V 


•377 




.439 


^s 


' 


.427 


•4375--438 








• SO 3 


^ 


' 


.489 


.500 -.5005 








.628 


1 




.616 


.625 -.6255 








.753 


1 * 




.734(11) 


.750 -.7505 







TAP DRILLS 
Double Depth of Threads 



65 



Threads 


V 

Threads 


U.S. 
St'd 


Whit. 
St'd 


Threads 


V 

Threads 


U.S. 

St'd 


Whit. 
St'd 


per in. 


DD 


DD 


D D 


per in. 


DD 


DD 


DD 


2 


.86650 


.64950 


.64000 


28 


.06185 


.04639 


.04571 


2i 


.77022 


•57733 


.56888 


30 


.05773 


.04330 


.04266 


2f 


.72960 


.54694 


.53894 


32 


.05412 


•04059 


.04000 


2h 


.69320 


.51960 


.51200 


34 


.05097 


.03820 


.03764 


2f 


.66015 


•49485 


.48761 


36 


.04811 


.03608 


.03555 


2f 


.63019 


.47236 


•46545 


38 


.04560 


.03418 


.03368 


2I 


.60278 


.45182 


.44521 


40 


.04330 


.03247 


.03200 


3 


.57733 


.43300 


.42666 


42 


.04126 


.03093 


.03047 


3i 


.53323 


.39966 


.39384 


44 


.03936 


.02952 


.03136 


3h 


.49485 


.37114 


.36571 


46 


.03767 


.02823 


.02782 


4 


.43300 


.32475 


.32000 


48 


.03608 


.02706 


.02666 


4l 


.38488 


.28869 


.28444 


50 


.03464 


,02598 


.02560 


5 


.34660 


.25980 


.25600 


52 


.03332 


.02498 


.02461 


5i 


.31490 


.23618 


.23272 


54 


.03209 


,02405 


.02370 


6 


.28866 


.21650 


.21333 


56 


.03093 


02319 


.02285 


7 


.24742 


.18557 


.18285 


58 


.02987 


.02239 


.02206 


8 


.21650 


.16237 


.16000 


60 


.02887 


.02165 


.02133 


9 


.19244 


.14433 


,14222 


62 


.02795 


.02095 


.02064 


10 


.17320 


.12990 


. 1 2800 


64 


.02706 


.02029 


.02000 


II 


.15745 


.11809 


.11636 


66 


.02625 


.01968 


.01939 


11^ 


.15069 


.11295 


.11121 


68 


.02548 


.01910 


.01882 


12 


.14433 


.10S25 


.10666 


70 


.02475 


.01855 


.01828 


13 


•13323 


.09992 


.09846 


72 


.02407 


.01804 


.01782 


14 


.12357 


.09278 


.09142 


74 


.02341 


.01752 


.01729 


15 


.11555 


.08660 


•08533 


76 


,02280 


.01714 


.01673 


16 


.10825 


.08118 


.08000 


78 


.02221 


.01665 


,01641 


18 


.09622 


.07216 


.07111 


80 


.02166 


.01623 


.01600 


20 


.08660 


.06495 


.06400 


82 


.02113 


.01584 


.01560 


22 


,07872 


•05904 


.05818 


84 


.02063 


.01546 


.01523 


24 


.07216 


.05412 


•05333 


86 


.02015 


.01510 


.01476 


26 


.0661 


.04996 


.04923 


88 


.01957 


.01476 


.01454 


27 


.06418 


.04811 


.04740 


90 


.01925 


.01443 


.01422 



This gives the depth to allow for a full thread in a nut or similar 
piece of work for threads for 2 to 90 per inch, regardless of the diam- 
eter. A special nut for a 2-inch bolt, 20 threads per inch, U. S, 
Standard would have a hole 2. — .06495 = 1.93505 inches in diam- 
eter bored in it. 



66 



TWIST DRILLS 



Sizes of Tap Drills for Taps with "V" Thread 





1 


1 




I 






K 


s" 




a 


■^ 


H-S 




P^ 


^-s 




Q 


H-g 




Q « 


h| 




Q s^ 




1l 


^1 


•i5 




•^ 




l-s 


-ol 




l-s 


^■s 


g.c 


^^ 


?^2 


1^ 




§^ 


rt.S 




^^ 


I.S 


l^g 


§^^ 


S 


H 


Cfi 


Q 


H 


w 


5'" 


H 


•(n 


Q 


H 


w 


^ 


48 


50 


3^ 


24 


No. 20 


if 


12 


fi 


lA 


7 


lei 


3^^ 


52 


50 


¥ 


28 


No. 17 


it 


14 


i 


lA 


8 


I6\ 


^\ 


54 


49 


^^ 


30 


No. 16 


f 


10 


M 


li 


7 


I.\ 


?\ 


56 


49 


3V 


32 


No. 15 


i 


II 


h 


lA 


7 


lA 


A 


60 


48 


if 


24 


No. 16 


1 


12 


If 


ifV 


7 


I^T 


^? 


32 


50 


il 


2S 


No. 1 2 


fi 


10 


If 


lii 


7 


lA 


^? 


36 


49 


if 


32 


No. 10 


li 


II 


il 


If 


6 


li 




40 


47 


i 


18 


No. 17 


M 


12 


If 


lif 


6 


1/2 


"&% 


48 


44 


i 


20 


No. 14 


;i 


II 


T^. 


i-V 


6 


lA 


eV 


56 


43 


i 


24 


No. 9 




12 


If 


I-f 


6 


1/2 


i 


32 


44 


3^ 


16 


No. 10 


If 


II 


if 




6 


li: 


i 


3(> 


43 


3% 


18 


if in. 


If 


12 


II 


1^1 


6 


l\: 


i 


40 


42 


3\ 


20 


No. 3 


f 


10 


II 


IT^6 


6 


l| 


i 


42 


41 


A 


16 


No. I 


f 


II 


A 


lit 


6 


I|^ 


1 


48 


39 




18 


if in. 


f 


12 




if 


5 


i|f 


^\ 


30 


41 


ii 


16 


F 


ft 


10 


64 


if 


5i 


i|f 


is\ 


32 


40 


i\ 


18 


il in. 


If 


II 


|- 


^W 


5 


I|^ 


^\ 


36 


37 


t 


14 


J 


If 


12 


¥¥ 




5i 


i|t 


A 


40 


34 


f 


16 


L 


il 


ID 


It 


ifi 


5 


i|^ 


-,% 


30 


33 


1 


18 


il in. 


¥ 


10 


f- 


iH 


5i 


i|t 


3\ 


32 


32 


if 


14 


N 




9 


If 


iff 


5 


III 


A 


36 


31 


if 


16 


P 


1 


10 


II 


i|f 


5^ 


III 




40 


30 


if 


18 


If in. 




9 


1 


If 


5 


III 


32 


30 


j'g 


14 


R 


il 


9 


-f 


i|f 


5 


i|f 


ri 


36 


29 


tV 


16 


S 


-^ 


9 


-f 


Iff 


5 


i|f 


■ji 


40 


28 


if 


14 


f in. 




8 


-;j 


ill' 


5 


i|f 


A 


24 


29 


15 
32 


16 


W 


I3V 


8 




li 


4i 


i|f 


A 


28 


28 


i 


12 


if in. 


II^ 


8 


-^^ 


li 


5 


III 


A 


30 


27 


i 


13 


X 


lA 


8 


If 


III 


4i 


Iff 


3 
T6 


32 


26 


i 


14 


if in. 




7 


II 


isf 


5 






36 


24 


il 


12 


It in. 


i\ 


8 


If 


I- 6 


4i 


iff 


il 


24 


26 


il 


13 


II in. 


lA 


7 


It 


I-l 


5 


iff 


if 


28 


22 


il 


14 


tV in. 


lA 


8 




I-l 


4i 


iff 


if 


32 


20 


A 


12 


II in. 


lA 


7 


If 


I-i 


5 


Iff 


if 


36 


18 


rV 


14 


if in. 


lA 


8 


leV 


2 


4i 


Iff 



This table gives similar information but in a way that would be 
more convenient in some cases. 



TAPPING AND THREADING 67 



TAPPING AND THREADING SPEEDS 

For tapping in cast iron, the F. E. Wells & Son Company, Green- 
field, Mass., recommends the following speeds: 



f inch holes 



382 255 191 153 127 

using an oil or soda compound. 
For soft steel and iron: 

i f i f I inch holes 

229 153 115 91 76 

using oil as a lubricant. 

The National Machine Company, Hartford, Conn., uses 233 revo- 
lutions per minute up to J inch diameter and 140 revolutions per 
minute for sizes between | and ^ inch, using a screw-cutting oil as 
a lubricant. 

They tap holes as deep as four tap diameters by power. 

For threading cast iron in machines of the bolt-cutter type, the 
Landis Machine Company, Waynesboro, Penn., gives these speeds: 

i f h f I I2 2 inches 

200 150 125 100 85 55 45 

with petroleum as a lubricant. 
For soft steel and iron : 

i f h f I i| 2 inches 

280 220 175 140 115 75 60 

with compound or screw-cutting oil, using a 2^-inch belt at 1200 feet 
per minute. The speeds are for high-speed steel dies. Some users 
run the machines at a much higher rate. 



Threading Pipe 

The Bignall & Keeler Manufacturing Company, Edwardsville, 
111., aims to have its pipe-threading machines run at a cutting speed 
of 15 feet per minute. The machine for handling pipe from I to 2 
inches uses a 3|-inch belt at about 940 feet per minute. They advise 
nothing but lard oil on the dies. 

The Standard Engineering Company, Ell wood City, Penn., also 
recommends a cutting speed of 15 feet per minute, using a 3-inch 
belt at 730 feet per minute. 

It will be understood in all the cases cited that the figures given 
are merely a guide as to what can be done and not record perform- 
ances in any particular. Soft stock can be run very fast, and hard, 
gritty stock is very hard on the dies. 

The only general rule, in the case of dies, is to run as fast as possible 
without undue heating of the dies. 



68 



TWIST DRILLS 



DRILL END LENGTHS 

It is often necessary in designing brass castings to allow for drilling 
to a certain depth so as to give the thickness of metal A necessary 
at the bottom of the hole to withstand pressure. 

The table gives the dimension C for usual sizes of drills. This 
is deducted from B to give the actual thickness of metal at A . 

Drill End Lengths 







Cin 


Gage 






Cin 


Gage 






Cin 


Dia. 


c 


near- 
est ,\ 


No. 


Dia. 


c 


near- 
est ,h 


No. 


Dia. 


C 


near- 
est o'4 


2 


0.60086 


If 


I 


0.2280 


0.06850 


0^5 


41 


0.0960 


0.02884 


T?2 


^"4 


0.58208 


64 


2 


0.2210 


0.06640 


C^ 


42 


0.0935 


0.02809 


3^2 


li 


0.56331 


A- 


3 


0.2130 


0.06400 


A 


43 


0.0890 


0.02674 


^^ 


^^1 


0-54453 


^1 


4 


0.2090 


0.06279 


iV 


44 


0.0860 


0.02584 


^z 


If 


0.52576 


u 




0.2055 


0.06174 


IV 


45 


0.0820 


0.02464 


3*2 


li^ 


0.50698 


1 


6 


0.2040 


0.06129 


A- 


46 


0.0810 


0.02433 




If 


0.48820 


u 


7 


0.2010 


0.06039 


IV 


47 


0.0785 


0.02358 


^¥ 


0.46942 


Vi 


8 


0.1990 


0.05979 


I^. 


48 


0.0760 


0.02283 


s 


'^ 


0.45065 


n 


9 


0.1960 


0.05888 


I^I 


49 


0.0730 


0.02193 


^ 


'<« 


0.43187 


/•T 


' 10 


0.1935 


0.05813 


^, 


50 


0.0700 


0.02103 


aV 


If 


0.41309 


hi 


II 


0.1910 


0.05738 


IV- 


SI 


0.0670 


0.02013 


3»2 


lA 


0.39431 


n 


12 


0.1890 


0.05678 


1^6- 


52 


0.0635 


0.01908 


e^S 


li 


0.37SS4 


i 


13 


0.1850 


0.05558 


^, 


53 


0.0595 


0.01788 


h 


^j\ 


0.35676 


n 


14 


0.1820 


0.05468 


A- 


54 


0.0550 


0.01652 


~h 


li 


0.33798 


a 


15 


0.1800 


0.05408 


^s 


55 


0.0520 


0.01562 


B^ 


iiV 


0.31931 


fi 


16 


0.1770 


0.05318 


^e 


56 


0.0465 


0.01397 


e^ 


I 


0.30046 


u 


17 


0.1730 


0.05197 


^e 


57 


0.0430 


0.01292 


6\ 


il 


0.29104 


i'i 


18 


0.1695 


0.05092 


# 


58 


0.0420 


0.01262 


B^ 


il 


0.28165 


^% 


19 


0.1660 


0.04987 




59 


0.0410 


0.01232 




M 


0.27226 


A 


20 


0.1610 


0.04837 


s\ 


60 


0.0400 


0.01202 


V 


i 


0.26288 


11 


21 


0.1590 


0.04777 


6^ 


61 


0.03Q0 


0.01172 


B4 


\'i 


0. 25349 


"i 


22 


0.1570 


0.04717 


,\ 


62 


0.03S0 


0.01142 


&i 


• 8 


0.24410 


i 


23 


0.1540 


0.04627 


# 


63 


0.0370 


0.01112 




¥ 


0.23471 


V 


24 


0.1520 


0.04567 




64 


0.0360 


0.01082 


B4 


f 


0.22532 


T?J 


25 


0.149s 


0.04491 


b'? 


6S 


0.0350 


0.01052 


h 


u 


0.21593 


5^2 


26 


0.1470 


0.04416 


e% 


66 


0.0330 


0.00991 


6^ 


u 


0.20655 


li 


27 


0.1440 


0.04326 


6^3 


67 


0.0320 


0.00961 




u 


0.19716 


U 


28 


0.1405 


0.04221 


B^i 


68 


0.0310 


0.00931 


6^3 


1 


0.18777 


A 


29 


0.1360 


0.04086 


#4 


69 


0.0293 


0.00879 


b\ 


M 


0.17838 


u- 


30 


0.1285 


0.03861 


# 


70 


0.0280 


0.00841 


B^S 


T% 


0.16900 


n 


31 


0.1200 


0.03605 




71 


0.0260 


0.00781 


b\ 


¥ 


0.15960 


A 


32 


0.1160 


0.03485 


72 


0.0250 


0.00751 


h 


h 


0.15022 


{'■z 


33 


0.1130 


0.03395 


B" 


73 


0.0240 


0.00721 


h 


¥ 


0.14083 


¥ 


34 


O.IIIO 


0.03335 


^. 


74 


0.0225 


0.00676 


b\ 


/,? 


0.13144 


1 


35 


0.1100 


0.03305 


^\ 


75 


0.0210 


0.00631 


^ 


a 


0.12205 


1 


36 


0.1065 


0.03200 


^\ 


76 


0.0200 


0.00601 


B^ 


t 


0.11266 


V 


H 


0.1040 


0.03124 


^\ 


77 


0.0180 


0.00541 


B»4 


u 


0.10327 


0^3 


38 


o.iois 


0.03049 


^ 


78 


0.0160 


0.00481 




i^e 


0.09388 


#2 


39 


0.0995 


0.02989 


^ 


79 


0.0145 


0.00436 




# 


0.08450 


3% 


40 


0.0980 


0.02944 


^, 


80 


0.0135 


0.00406 




i 


0.07511 


«\ 


















Tf- 


0.06572 


1^0- 
















A- 

t 


0.05633 


3 






Fon 


iiuIa,C= 


0.60086 DUm. 






0.04942 
0.037SS 


g 






f^ 


^S 


'^MM 










0.02817 
0.01878 
0.00939 


A 






K 


^^ 


\!//' 








s 








^P^ 


Wmi 



















MACHINE SCREW TAPS 



69 



^-^^ 



y .^-G-H 



Dia. of Neck =Eoot Dia. 




Dimensions of Machine Screw Taps 









M 




UH UH 

















°,.r^ 


M 















^ 


ii 




^ 


-T3 




ja-Td 


43 j3 




t-l 








Number of 
Tap 




111 


i 

3 






s 


II 


(DC/3 




6 




Q 


2 


H 


J 


h:i K^l 




Q 


k1 


C/2 


:z; 




A 




B 


C 


D E 




F 


G 


H 




I 


.071 


64 


i| 


T% 


g It 


V 


.125 


t\ 


^\ 


3 


li 


.081 


56 


li 


T% 


T3 It 


V 


.125 


^ 


3\ 


3 


2 


.089 


5^ 


li 


T^W 


^ . It 


V 


.125 


l'^ 


^^. 


3 


3 


.101 


48 


i^ 


ft 


"" g ^' 




.125 


t\ 


3\ 


3 


4 


•113 


36 


2 


H 


-^1 It 


^w. 


•125 


r\ 


^ 


3 


5 


.125 


36 


2i 


f 


^ 1 




.125 


if 


A 


3 


6 


.141 


32 


2i 


i 


i| 




.141 


3^ 


eV 


3 


7 


•154 


32 


2i 


f 


^ i| 




•154 


■^'7, 


eV 


3 


8 


.166 


32 


2i 


if 


i IT 


^^ 


.166 


/^ 


i 


4 


9 


.180 


30 


2i 


^ 


i I^ 




.180 


1 
4 


i 


4 


10 


.194 


24 


2i 


1 


i il 




.194 


i 


^\ 


4 


II 


.206 


24 


2| 


^ 


i I^ 




.206 


i 


3^« 


4 


12 


.221 


24 


2f 


H 


t ^^ 


V 


.221 


^^2 


<2 


4 


13 


•234 


22 


2i 


I 


tV la 


% 


.234 


-,% 


t^w 


4 


14 


.246 


20 


2ft 


ItV 


T^^ li 


- 


.246 


j\ 


tV 


4 


15 


.261 


20 


2| 


li 


T6 l3 


-'« 


.261 


tV 


T^« 


4 


16 


.272 


18 


2f 


I^ 


t\ II 


-V 


.272 


fv 


/^ 


4 


18 


.298 


18 


2f 


li 


t\ n 


-V 


.298 


T^^ 


^v 


4 


20 


.325 


16 


3 


li 


i i^ 


- 


•325 


M 


i 


4 


22 


•350 


16 


3 


li 


i il 


- 


.■7crc 


ii 




4 


24 


.378 


16 


3i 


li 


tV h 


-* 


.378 


t 


s% 


4 


26 


.404 


16 


3i 


li 


t\ i^ 


6 


.404 


t 


fV 


4 


28 


.430 


14 


3i 


I* 


T^ I^ 




•430 


it 


T^^ 


4 


30 


.456 


14 


3i 


If 


T^6 I- 


lI 


.456 


I'e 


ii 


4 



These are for the American Screw Company's Standard screws 
that have been in use for many years. 



70 



TAPS 



Machine Screw Taps- 






(Wells Bros. Co.) 









Outside 










Size 


Threads 
per Inch 


Size 
steel 


Dia. Thread 


Whole 
Length 


Length 
Thread 


Length 
Square 


Diara. 


Max. 


Min. 


Square 








A 


B 


C 


D 


E 


o 


80 


147 


.063 


.061 


lA 


V 


t72 


.112 


I 


72 


147 


.076 


.074 


If 




1^5 


.112 


2 


64 


147 


.089 


.088 


i5l 


l\ 


^5 


.112 


3 


S6 


147 


.103 


.101 


isi 


f 


Tf5 


.112 


4 


48 


147 


.116 


.114 


iVn 


38- 


3\ 


.112 


5 


44 


147 


.i2g 


.127 


m 


\l 


1^5 


.112 


6 


40 


147 


.142 


.140 


2^, 


\l 


t75 


.112 


7 


36 


105 


•155 


•153 


2^\ 


\ 


\ 


.124 


8 


36 


174 


.169 


.167 


2h 


11 




• 131 


9 


32 


187 


.181 


.179 


2A 


\% 




.140 


lO 


30 


200 


.194 


.192 


2il 


\\ 




.150 


II 




215 


.206 


.204 


2\ 


I 


~i 


.161 


12 


28 


226 


.220 


.218 


2A 


I^-^ 


A 


.170 


13 




252 


•239 


• 237 


'?! 


I^^ 


# 


.189 


14 


24 


252 


.246 


• 244 


2\\ 


III 


T?2 


.189 


15 




258 


.258 


.256 


2 f 


li 


?'^ 


•194 


i6 


22 


278 


■ 273 


.270 


23^ 


i| 


'^% 


.209 


i8 


20 


304 


.299 


.296 


2 1 


I3\ 


A 


.228 


20 


20 


iil 


■325 


•322 


2i3 


lA- 


/s 


.249 


22 


18 


370 
366 


•351 


•348 


2\ 


13^2 


l"« 


.278 


24 


16 


387 
383 


•377 


•374 


2\l 


13% 


A 


• 215 


26 


16 


418 
414 


•403 


.400 


3 


lA 


^J 


.236 


28 


14 


449 
445 


•430 


.427 


35V 


If 


W 


• 249 


30 


14 


480 
476 


.456 


•453 


3i 


I/. 


u 


.268 





Pitch Dia. 


Size 


Pitch Dia. 

• 


Size 


Pitch Dia. 


Size 
















Max. 


Mm. 




Max. 


Min. 




Max. 


Min. 


X80 


•0538 


.0528 


7 X36 


• 1359 


•1345 


16 X22 


.2421 


2403 


I X 72 


.066 


.065 


7 X32 


• 1337 


•1323 


16 X 20 


.2394 


2374 


I X64 


•06s 


.064 


7 X30 


.1325 


• 131 


18 X 20 


.2652 


2634 


2 X64 


.078 


.0769 


8 X36 


.1489 


•1475 


18 X 18 


.2618 


2598 


2 X 56 


.0767 


.0756 


8 X32 


.1467 


•1453 


20 X 20 


.2912 


2894 


3 X56 


.0897 


.0S86 


8 X30 


• 1454 


.144 


20 X 18 


.2878 


2858 


3 X48 


.0879 


.0868 


9 X32 


.1598 


.1583 


22 X 18 


•3138 


3118 


4 X48 


.1010 


.0998 


9-X30 


.1584 


.1569 


22 X16 


•3094 


3074 


4 X40 


.0984 


.0972 


9 X 24 


• 1532 


.1517 


24X18 


•3398 


3378 


4 X36 


.0967 


•0955 


10 X 30 


.1716 


.170 


24 X 16 


.3354 


3334 


5 X44 


.1129 


.1116 


10 X32 


.1729 


.1713 


26 X 16 


.3614 


3594 


5 X 40 


.HIS 


.1102 


10 X 24 


.166 


.1647 


26 X14 


•3557 


3537 


5 X36 


.1098 


.1085 


12 X 28 


.1961 


.1944 


28 X 16 


■^^o^ 


3854 


6 X 40 


.1246 


.1232 


12 X 24 


• 1927 


.1907 


28 X 14 


.3818 


3797 


6X36 


.1229 


•1215 


14 X 24 


.2184 


.2167 


30 X 16 


•4154 


4134 


6X32 


.1207 


•II93 


14 X20 


.2134 


.2114 


30 X 14 


.4077 


4056 



HAND TAPS 



71 




Dimensions op Hand Taps 
(Wells Bros. Co.) 



Small Shank Taps 

U. S. S., Whit, and 

all V Taps Incl. 

aV over 



Size 


Pitch 


Total 


Length 


Length 


Length D 


iam. 


Diam. 


Length 


Thread 


Shank 


Square Sq 


uare 


Shank 






A 


B 


C 


D 


E 


F 


i 


20 


2 ^ 


U 


145 


.% 


134 


• 173-175 


i';, 


18 


2 


iiV 


I/. 


TB 


176 


.228-230 


1 


16 


2 


^t 


I f 


f 


217 


.283-. 28s 


<« 


Ji, 


3 5 


I • 


I f 


M 


254 


■330-.332 


1 


St'd 


3 f 




I 1 


T^T 


286 


•373--375 


<« 


12 


3 f 




2 


§ 


321 


•429 


1 


II 


3i5 




2l^, 


41 


359 




479 


iJ 


II 


4, 




2i 


41 


406 




542 


1 


10 


4i 


2 


2\ 


li 


442 




590 


i| 


10 


4i'.i 


2i 


2A 


H 


489 




652 




9 


4ii 


2i 


2/ii 


f 


523 




697 


ii 


9 


4l 


2| 


2i 


n 


569 




759 


I 


8 


5i 


2x^,1 


2ii 




600 




800 


1,^8 


St'd 


5i 


2r^T 


2}^ 


8 


647 




862 


^^ 


7 


5/.- 


2f 


2^ 


§3 


672 




896 


14- 


7 


Si's 


2}.\ 


2l 


-3I 


719 




959 


li 


7 


5iJ 


2 f 


2\% 


I 


766 


I 


021 


'^:* 


St'd 


5ii 


2}i? 


3 


Il^a 


813 


I 


084 


If 


6 


6 


2j 


3l 


iiV 


831 


I 


108 


ii> 


6 


n 


2iS 


3/,^ 


li 


878 


I 


170 


li 


6 


6i 


3 


3i 


Ij 


925 


I 


233 


lA 


St'd 


6/, 


3^ 


3t 


Il'g 


971 


I 


296 


If 


St'd 


6i«. 


3l 


3/b 


lA- 


978 


I 


305 


"i^ 


St'd 


M 


3i\ 


3§ 


li 


025 


I 


367 


I f 


S 


61 3 


3i 


3t^,t 


li 


072 


I 


430 


III 

1 1 


^ ?. 


7 


3A 


3i^ 


lA 


119 


I 


492 


St'd 


7 - 


3l 


3f 


lA I 


139 


I 


519 


lii- 


St'd 


7i 


3/,T 


3Jg 


If 


186 


I 


582 


2 


4f 


7t 


M 


3l 


If 


233 


I 


644 


2- 


c4* 


7i?, 


3l 


4t^t 


If I 


327 


I 


769 


2 i 


St'd 


7tl 


3l 


Az\ 


I/. I 


421 


I 


894 


2 - 


St'd 


8i 


3l 


Ai 


i/b 


514 


2 


019 


2 ^ 


4 


8^ 


4 


Ah 


l/e I 


575 


2 


100 


2- 


4 


su 


4 f 


A\}. 


l| I 


668 


2 


225 


'f 


St'd 


9i'.^ 


4 4 


A\l 


li 


762 


2 


350 


2| 


St'd 


9l 


4 - 


5 


11^6 I 


856 


2 


475 


3 


3i 


9f 


4 3 


5i 


lA 


906 


2.542 



72 



TAPS 



o 



m 



-G— 



Wi 



Regular Lengths over all 
are 11, 12, 14 aiid 15 Inches. 



Dimensions of Tapper Taps 













^-d 






?! 








o 





« 








Diameter of 


Number 


f^ 






Diameter of 


Diameter of 


E 


Tap 


per 


Inch 




c 


£5l 

H-1 


Shank E 


Point F 


"o 

1 


A 


U.S. 


V. 


B 


D 


u s. 


V. 


US. 


V. 




St'd 


St'd 


Sfd 


St'd 


St'd 


St'd 




t 


20 


20 


If 


li 


1 


0.170 


0.150 


0.179 


0.158 




A 


i8 


i8 


2 


li 


f 


0,225 


0.200J 0.234 


0.210 




f 


i6 


i5 


2 


li 


f 


0.280 


0.250^0.287 


0.261 




^ 


14 


14 


2i 


if 


* 


0-330 


0.300^0.338 


0.307 




h 


13 


12 


2i 


If 


1 


0.3^5 


0.3400.393 


0.348 




f^ 


12 


12 


2 + 


't 




0.440 


0.400 0.446 


0.41 1 




f 


II 


II 


2^ 


i^ 




O.dQO 


0.4550.499 


0.462 




ii 


II 


II 


2I 


i^ 




0.555 


0.515 0.561 


0.523 




A 


lO 


lO 


2i 


It 


li 


0.605 


0.560 o.6ti 


0.570 




¥ 


lO 


lO 


2| 


i| 


If 


0.670 


0.625 0.673 


0.631 




i 


9 


9 


3 


If 




0.720 


0.675 0.722 


0.675 




if 


9 


9 


3 


li 




0.780 


0.7300.783 


0.736 




I 


8 


8 


3i 


2 




0.820 


0.770 0.828 


0.775 




i| 


7 


7 


3^ 


2 




0.925 


0.860 0.928 


0.869 




li 


7 


7 


3^ 


2 




1.050 


0.985 1.053 


0.993 




If 


b 


6 


4 


2f 




I-I45 


1.070 1. 147 


1.075 




• ih 


5 


6 


4 


2f 


I* 


1.270 


1. 1951.272 


1.200 





Note. — Tapper taps differ from machine taps in not having a 
square on the end of the shank. They are used in nut tapping 
machines, the nuts being run over the tap on to the shank and when 
full the tap is removed and the nuts slid off. The tap is then re- 
placed for another lot of nuts. 



PIPE TAPS 



73 




bo 
1 


o 


■^^OOOCT. OrOrOO \O00»OM 




1 

o 


NvOO^rO liOOOOOM 0<N0viO 




ajnij 


•^TJ-'trJ-Tt lOioOO OOOO 




•spqx 


WOOOO'*^ "mm'^mm COOOOOCO 




1 

.£2 
Q 


Ul 


COtSMMf-. ^00<NO 00VOIJ--IO 

(NfO^iovO OOOvH^a- voOvwiN 




H-> 


MHMM CN<NOCO 




K 






o 






fin 






' 


w 


■"•n "h "2 ""n ^r? '*' "'"' '-*"' '^'' "'" '-''" "''^ "'"' 




fi -""-"-= ~-„t rr-rr 




u 


nla> mgo -<IM m-< t-W -<K -i|« nl-« ^^^ <-::» ^li 




pq 


"Wi --5 -S "W "1" WW BM nw MM c^; «;«. 1^ m* 

MHMM MMHM MN<NCI 










t^OOOO-*'* MMMM 00000000 






azjS 


w w w N N to to t 


i 



74 



TAPS 



o 
u 

o 



V 



ii 







(N 




0^ 


On 


t^ 





PO 


H 


M 


ro 


10 


CO 





'^ 






• 


M 




M 








Q 


■H« 


.Hl-Jl 


rHi-* 


< 


'^in 




nloo 


o 


M 


nloo 


H2 
M 






H2 

M 


«loo 

M 






t-lM 


r-IlM 




i-l[M 


to 




m 


rHl^ 


c,|« 




H 


m\m 


H 


M 


<; 


«|C0 


1-1^ 




HN 


rHlN 


«|« 


t-|0O 






<N 




<N 


CN 


<N 


C^ 


^ 
















l^ 


CO 


CO 


CO 


C/3 


CO 


CO 


C/2 


^^ 


^^ 


^c/3 


r^^ 


^c/^ 


^^ 


J?^ 


^^ 


8^ 


0^ 


8^ 


8^ 


0^ 


0^ 


0^ 


^rt 


' 


■ 00 


■ 


■ '^ 


w 


' <N 


■ 


Pin 




M 


M 


M 


M 


M 


M 


8i 


^- 











-* 


ON 


OO 







LO 





On 


'^i- 




P^Q 


q 


^ 








CN 


- 




















s 


.3 


00 








Tt 


M 


00 


00 




M 


10 


00 





ro 


00 




i 


M 




M 




<N 


<N 


CO 




































Q 


















J2 


^ 
S 





CN 


<N 





fO 








>r 




10 


00 





rO 


Ch 






"• 


M 


M 




cs 


<N 


CO 


(H 




















.9 


uo 


^O 





r^ 


C) 


t^ 


cs 


V 












■sO 




10 


5 


S 


I-; 






(N 


M 


CO 


CO 




















t^ 


00 


IN 





ro 





10 


CA 


rt 


<N 










-O 




LO 


° 


^ 




M 




(N 




CO 


CO 


«-^T3 


t^ 


^ 


>o 


C^ 


00 


00 







tJ- 


t^ 




10 




(N 


t^ 




M 


- 


<N 


<N 


CO 


CO 


^1^-5 


c 


00 


•^ 


<N 


00 


00 


vO 


52;^ aj 


rO 








M 


M 


M 


o 





rtloo 


-^ 


-'^ 


-% 


i-(|-* 


'^ 


«|«) 



TAPER DIE TAPS 



75 



k-F- 





— B- 



DJam. of Shauk Eopt Diam. less 0.015 

Dimensions of Taper Die Taps 



Diameter 


Length 


Length 


Length 


Total 


Length 


Size 


Number 


of 
Tap 


of 
Shank 


of 
Thread 


Straight 
Thread 


Length 


of 
Square 


of 
Square 


of 
Flutes 


A 


B 


c 


D 


E 


F 


G 




i 


li 


2 


i 


3i 


T% 


i 


5 


A 


li 


2-} 


t\ 


4 


i 


iV 


5 


f 


i^ 


3 


* 


4i 


H 


A 


5 


tV 


If 


3} 


tV 


5 


H 


i 


5 


h 


2 


3i 


i 


5^ 


f 


3^^ 


5 


A 


2i 


3f 


T^IT 


6 


if 




5 


f 


2^ 


4 


ft 


6i 


if 


11 


5 


H 


2f 


4i 


H 


7 


^ 


M 


6 


i 


3 


4^ 


f 


7^ 


1 


tV 


6 


it 


3i 


4f 


H 


8 


if 


i 


6 


1 


,S^ 


5 


^ 


8J 


I 


i 


6 


if 


3^ 


5i 


H 


8f 


I 


A 


6 


I 


3i 


5^ 


I 


9 


ItV 


ft 


6 


li 


3^ 


5i 


ih 


9i 


ll 


if 


6 


li 


3^ 


6 


li 


9* 


itV 


f 


7 


If 


3ft 


6i 


Ift 


9f 


lA 


if 


7 


i^ 


3ft 


6t 


I* 


lO 


if 


1 6 


7 


If 


3f 


6ft 


Ift 


loi 


I 16 


I 


7 


If 


3ft 


6J 


If 


loj 


ih 


II^^ 


8 


i| 


38 


7* 


I^ 


lof 


if 


li 


8 


2 


3f 


7f 


2 


II 


lif 


li 


8 



76 



TAPS 



h-H-^ 




Dimensions of Sellers Hobs 













X 










'o 






o 


"o o 


Sf 









s 


6 o 

.2K 


Number of 
Threads 
per Inch 


Diameter 

of Pilot 

B 


HI 


•5 "3 

Ut-H 


^^1 


■3 


Diameter 

of Shank 

G 




0£ 




Q 






hJ 


h-1 


h:i 


H 




^ 


CO 


^ 


A 


U.S. 
St'd 


V. 

St'd 


U.S. 
St'd 


V. 

St'd 


c 


D 


E 


F 


U.S.St'd 


V. St'd 


H 


J 




i 


20 


20 


A 


A 


2 


li 


li 


4i 


0.170 


0.150 


f 


i 


6 


T^« 


i8 


i8 


tV 


T^« 


2 


li 


li 


4i 


0.225 


0.200 


f 


■^'2 


6 


1 


i6 


i6 


i 


i 


2i 


ly'fi 


ItV 


•S 


0.280 


0.250 


f 


t\ 


6 


V^ 


14 


14 


tV 


i 


2i 


it\ 


lA 


,si 


0-330 


0.300 


H 


i 


6 


i 


13 


12 


t 


tV 


2i 


iH 


lit 


s^ 


0.385 


0.340 


H 


J% 


8 


t'w 


12 


12 


t 


f 


2} 


li 


li 


6 


0.440 


0.400 


If 


tV 


8 


^ 


II 


11 


i 


t 


2i 


2i 


2i 


6i 


0.490 


0.455 


i 




8 


ii 


II 


II 


i 


i 


2i 


2i 


2^ 


7 


0-55S 


0.515 


i 


it 


8 


i 


lO 


lO 


i 


i 


2i 


2i 


2i 


7i 


0.605 


0.560 


i 


Tfi" 


8 


i* 


lO 


lO 


i 


i 


2i 


2f 


2f 


8 


0.670 


0.625 


n 


i 


8 


^ 


9 


9 


^i 


i 


2i 


^ 


3 


8i 


0.715 


0.675 


H 


i 


8 


i^ 


9 


9 


H 


H 


2i 


■si 


3i 


9 


0.780 


0.730 


I 


9 
Tfi 


10 


I 


8 


8 


H 


H 


2ft 


3i^6{3iV 


9i 


0.825 


0.770 


I 


ft 


10 


li 


7 


7 


i 


Ti 


2ft 


3^3t^ 


9f 


0.925 


0.860 


itV 


H 


10 


li 


7 


7 


8 


i 


2ft 


3HI3H 


10 


1.050 


0.9S5 


ItV 


i 


10 


ll 


6 


6 


iiV 


i 


2ft 


3l^i3it 


loi 


1. 145 


1.070 


li 


H 


10 


li 


6 


6 


itV 


itV 


2ft 


4t'6I4T6 


II 


1.270 


1.200 


I^ 


H 


10 


I^ 


5^ 


5 


lA 


li 


2f 


4f 


4t 


iii 


1-375 


1.265 


li 


I 


12 


ll 


5 


5 


IT^W 


Ifv 


2| 


4ft 


4t 


12 


1-475 


1.390 


li 


itV 


12 


li 


5 


4i 


li 


IT% 


2i 


4i 


4i 


I2i 


1.600 


1-475 


IT% 


li 


12 


2 


4i 


4h 


li 


li 


2f 


5i 


5i 


13 


1.700 


1.600 


if iii 

1 


12 



Note. — The Sellers hob is designed to be run on centers, the 
work, such as hand or die chasers, being held against it and fed 
along by the lathe carriage. 



SQUARE THREAD TAPS 




-D — 



-E 



77 



>f-FH 



Standard Square-Thread Taps 



Size 


A 


B 


c 


D 


E 


F 


G 


H 


I 


Diameter f. .d) 

(2) 

Pitch 8 (3) 

Diameter f^.-d) 

(2) 

Pitch 6 (3) 

Diameter f". .(i) 

(2) 

Pitch 4I (3) 

Diameter i". .(i) 

(2) 

LeadD'BLr(3) 

Diameter ij. . (i) 
(2) 
(3) 

Pitch 3i (4) 

Diameter if" .(i) 
(2) 
(3) 

LeadD'BL i" (4) 


If 

¥ 

It 

I 

It 

rr 


f 

47 

it 
If 

¥ 

itV 

li 

lit 

itV 


h 

ii 
II 

li 
li 

If 

if 
li 

i4 

li 
li 


4 

3l 

3f 
3! 
3l 

4 
4 
4 

4l 
4i 

4i 

4f 
4l 

4f 
4i 

5i 
5i 
5i 
5i 


3i 
3i 
3i 

3f 
3f 
3f 

3f 

3f 

4i 

fi 

4f 
4f 

4l 
4l 

4f 
4f 
4f 
4f 


f 


t\ 

ft 

3 

4 

f 
f 

if 

II 

it 

li 
l| 
li 

li 


1 
f 
f 

f 
f 

1 
1 

li 
li 
li 
li 

If 
If 
If 
If 


ii 

h 
h 

1 
f 
f 

if 

il 

i 

1 

7 
8 

1 



Note. — While in theory the thread and the space are both one 
half the pitch in practice it is necessary to make the thread a little 
more than half in order to allow clearance for the screw that goes 
into the threaded hole. The amount of this clearance depends on 
the character of the work and varies from .001 inch up. Some also 
make the tap so that the screw will only bear on the top or bottom 
and the sides. 



FILES 

Files are designated both by the spacing of their teeth and the- 
shape or cross-section of steel on which the teeth are cut; the size 
always referring to their length which is measured from the point 
cutting to the end of the file proper but the measurement never 
includes the tang which fits into the handle. 

Terms Used 

The back of a file is the convex or rounding side of half-round, 
cabinet and other files having a similar shape. 

A file is Bellied when it is full or large in the center. 

A Blunt file is the same size its whole length instead of being tapered. 

An Equalling file is one which looks blunt but which has a slight 
belly or curve from joint to tang. 

A Float file is a coarse single cut made for use on soft metals or 
wood and frequently used by plumbers. 

A Safe-edge is an edge left smooth or blank so that the file will not 
cut if it strikes against the side of a slot or similar work. 

The Tang is the small pointed end forged down for fitting into the 
handle. 

Three square files are double cut and have teeth only on the sides, 
while taper saw files are usually single cut and have teeth on the 
edge as well as the sides. This makes the taper saw files broad on 
the edge or without sharp corners, while the three square files have 
very sharp corners. 

A special angle tooth file is made for brass work. The first cut is 
square across the file, while the second is at quite an acute angle, 
about 60 degrees from the first cut. 

Doctor files are very similar to these except that the first cut is 
about 15 degrees instead of being square across the file. 

A lock file has safe edge and the teeth only go about one third the 
way across from each side leaving the center blank. The teeth are 
single cut. 

HiGHT OF Work 

The work should be at a convenient hight which will usually vary 
from 40 to 44 inches for most men with an average of 42 inches. 
This means the hight of the work, not the bench. 

Pickling Bath 

A good pickle to soften and loosen the scale on cast iron before 
filing is made of two or three parts of water to one part of sulphuric 
acid. Immerse castings for a short time. 

For brass castings use a pickle of five parts water to one part nitric 
acid. 

78 



TOOTH SPACING 



79 





BASTARD 



r 



SECOND CUT SMOOTH 

Actual Tooth Spacing of Single Cut Files 





SMOOTH DEAD SMOOTH 

Actual Tooth Spacing of Double Cut Files 



8o FILES 

The Teeth of Files 
The cut of a file or the number of teeth per inch vary with the 
length of the file itself and the kind of a file, and is a little confusing, 
as a rough cut in a small file may be as fine as a second cut of a 
larger size. The cuts used on regular 12-inch files are shown in the 
illustration and represents the practice of Henry Disston & Sons. 
The same makers also supply the table of cuts per inch used on their 
machines, which are as follows: ^ 

Regular Taper Files 
Length, inches. — 2^, 3, 3!, 4, 4*, 5, 5 J, 6, 6^, 7, 8, 9, 10, 
Teeth per inch — 64, 56, 52, 50, 48, 46, 44, 42, 42, 40, 38, 36, 34. 
Slim Tapers — 64, 64, 60, 58, 56, 52, 50, 50, 46, 46, 44, 40, ^S. 

Mill File, Bastard Cut 
Length — 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20 in. 
Teeth — 56, 50, 48, 46, 44, 42, 40, 38, 36, 34, 32, 30, 28, 26, 24, 22 
per inch. 

Flat File, Bastard Cut 
48, 42, 38, 36, 32, 30, 26, 24, 22, 20, 20, 18, 18, 16, 16, 14. 
Single cut files usually have teeih at about 25 degrees and in double- 
cut files the other cut is usually from 45 to 50 degrees. Fine 
machinists files are made in ten numbers from 00 to 8. 

The Shapes of Files 
In the following pages the shapes of standard files are shown. 
The names are as follows: 

1. Metal saw — blunt. 6. Round or rat-tail. 12. Warding. 

2. Three-square or tri- 7. Pippin. 13. Extra narrow 

angular. 8 Knife. pillar. 

3. Barrette. 9. Crossing. 14. Narrow pillar. 

4. Slitting, 10. Half-round. 15 Pillar. 

5. Square. 11. Crochet. 16 Hand. 

Files are cut in two ways, single and double The first has but a 
single line of cuts across the surface, at an angle with the file body 
but parallel to each other. The double-cut file has two lines of cuts, 
at an angle with each other, and the second cut being usually finer 
than the first. Some prefer the single cut, for filing in the lathe. 
Rasps have single teeth forced up with a punch. 

The old method of designating the cuts were rough, coarse, bas- 
tard, second cut, smooth and dead smooth. . Some makers are now 
using a series of numbers — usually eight to ten — instead of 
the six designations by name formerly employed. The uses of the 
various cuts depend on the shop in question and m.ust be learned from 
observation and experience in each case. 

The grades of cut used by them run from No 00 to No. 8, and while 
it is hard to exactly compare them with the old-style designations, it 
will be found that No. 00 is about the same as a bastard. No. i as a 
second cut, No. 2 or 3 with a smooth, and Nos. 6 to 8 with a dead 
smooth file. 



SHAPES OF FILES 



8l 

<] 



<] 







n 



y v,,ij:wwMs. 




The Standard Shapes of Files 



82 



FILES 



Wf' 



¥/W^'f.''yf/f'''yf>)!f/'^j,/y//^l:'W''J'-y 'ff/f, yy,,,/J>^^^^^^ . , .„,.m)^y. 




\ ■ i 


13 






14 






15 









The Standard Shapes of Files 



When a File Cuts Best 

One who has given the matter careful attention, and has built 
file-testing machines, Edward G. Herbert, of Manchester, England, 
has come to the conclusion that a file does not cut best when it is 
new but after it has been used for some little time, say 2500 strokes 
or the filing away of one cubic inch of metal. Another curious 
feature is that its usefulness seems to come to a sudden instead of a 
gradual end. 

A bastard file having 25 teeth to the inch, operating on a surface 
one inch square with a pressure of 30 pounds, which is about equal 
to heavy hand filing, gives 25 cutting edges about one inch long, 
which likens it somewhat to a broad cutting tool in a planer. 

In cutting a file the metal is forced up in a sort of a bur, and occa- 
sionally the top of the tooth slopes over backward which is the reason 
that a file often cuts better after these are broken or worn off. Then, 
too, when a file is new all the teeth are not of the same hight and 
only a few points cut. As they wear down more teeth come into 
contact and do more work. 



SMALL FILES 



83 



:wmMwmfmm/!m& ,r 



r- 


--— .„-:_„-^,.-.^..^.„_^Stt:.;^ 




1 


















■ii 






) 










La_ 






) 








... J 










K* 


WSfM^^SS!:!i:!:::;L : 




J 



Needle Files for Fine Work 



==^ 



^^^ 



Die Sinkers Files or Riffles 



84 



WORK BENCHES 



WORK BENCHES 

The duties of a bench vary with the shop in which it is located 
according to the work that is to be done on it or at it. If it is simply 
a fihng bench, the main requirement is that it support a vise firmly 
and at the proper hight. If an assembling bench, these are not the 
important features, and just what it does need depends on the kind 
of work being handled. 

For the average shop work we want a bench that is rigid; that will 
stand chipping and filing; that can be used in testing work on a 
surface plate or in handling jigs and fixtures; that will not splinter 
badly nor yet injure a tool should it happen to drop on it. For the 
toolmaker the cast-iron bench top has many advantages, but both 
the bench and the tool are very liable to be marred by dropping the 
tool on it, so that for general use we rely on wood as in the days of 
old, except that a bench with solid 2- or 3-inch planking the whole 
width is now too expensive to consider. We no longer want the 
bench braced up against the side of the shop but set it out from 




JFIG. 1. Good for Ordinary Work 



FIG. 2. Another Method. 



the wall to allow the heat to rise and the air to circulate, as well as 
giving the sprinklers a chance to get at a fire on the floor near the 
walls. 

The use of a lighter board at the back has become so common that 
the New Britain Machine Company's design for a bench leg is made 
for this construction as shown in Fig. i. This also shows the back- 
board B rabbeted to the plank A, which supports it all along the 
front edge, and it is also supported by the stringer D, which runs the 
whole length of the bench. These supports, in addition to the cross 
bearing of the legs every 6 or 8 feet, give the backboard a stifl'ness 
that was unknown where they are simply laid flush and not rabbeted 
and the stringer is absent. 

Benches made without these supports are open to the serious objec- 
tion that the backboard springs down when a heavy weight, such as 
a jig or surface plate, is put on the bench and throws them out of 
level. 

All cracks are more or less of a nuisance in bench work, but in 
this case any shrinkage can be taken up by wedging against the 
iron, support of the board C and the edge of the backboard B. 



WORK BENCHES 



8S 



Another style bench with this same leg is shown in Fig. 2, Here 
the front plank A and the backboard C are the same as before, but 
instead of having one backboard, this part of the bench is made up 
of narrow strips as B, fitting into rabbet in plank A and supported 
by the stringer D as before. These narrow boards can be either 
tongued and grooved hardwood flooring, or can be square edges, as 
preferred; in either case any shrinkage can be taken up by forcing 
the boards together. 

A cheaper form of bench is shown in Fig. 3, where the heavy 
planking is entirely dispensed with and the boards B run the full 
width of the bench as shown. Running along the front, underneath 
the main boards is a soft plank A which supports the edge of the 
bench where the most work comes, and under the back is the 2X6- 
inch stringer as before. Here, too, the boards can be either notched 
or square edge, each having its advocates; the objection raised 
against the tongue and groove being that the edges are apt to split 
off from heavy articles dropping on them. An advantage claimed 
for the boards running this way is that work going on or off the 




FIG. 3. A Cheaper Way. 



FIG. 4. A good but 
expensive Construction. 



bench is always in the direction of the grain of the wood and that 
fewer splinters are formed on that account. In either Figs. 2 or 3 
any local wear can be remedied by replacing the worn board with a 
new one. Some object to the end of the grain at the front of a bench. 

The material used in any of these can be varied to suit the indi- 
vidual requirements. Maple is generally considered the best wood 
for a bench, while others prefer ash. For the backboards hard pine 
is often used and even cheaper woods will answer if necessary, al- 
though it probably pays to use maple all through if you can afford 
it. 

Still another style of bench is shown in Fig. 4 and one which was 
designed to be serviceable and have a long life without so much 
regard to first cost as the others. The bench leg was flat on top, 
the first layer of maple planks A and D and on top, narrower boards 
of the same material. These were fastened with long wood screws, 
holes being countered and plugged as shown. 

The theory of this construction is that the boards are sure to be 
more thoroughly seasoned than the planks, consequently the planks 



86 SOLDERINCi 

will shrink the most and tend to draw the top boards closer together. 
It certainly makes a solid bench, but the first cost is rather high. 

Benches are also occasionally built up from small blocks so as to 
present an end grain on the top, the same as butchers' blocks. One 
shop we know of surfaces these when worn by putting them on a 
Daniels' planer and substituting a circular saw for the swinging 
knives. This saws the top very smooth and leaves a good surface. 
Others glue up strips on edge and plane down to a smooth surface 
so as to do away with all cracks. Zinc or even heavy paper covers 
are often used where fine work is being assembled to prevent its 
finding its way into cracks and crevices. 

The usual work bench is from ^^ to 35 inches from the floor to the 
top, abolit 29 or 30 inches wide, and has the front plank 3 inches with 
backboards i inch thick. A cast-iron leg of this type weighs about 
50 pounds. 



SOLDERING 

Almost every one thinks he can solder, yet if we examine the 
work carefully we will find that only about 10 per cent of the work 
is really done as it should be. Thorough soldering is frequently 
referred to as sweating, and it is remarkable the difference in strength 
between a well-fitted and "sweated" junction of the metals and 
one as ordinarily soldered. 

A point frequently overlooked is the important one of properly 
cleaning the surfaces to be joined. This is too often left for the 
flux to correct. Another neglected point is the selection of the flux 
to be used, although nearly all of the metals can be joined by the use 
of the same flux. The after effects resulting from improper cleaning 
after soldering are frequently worse than the good effects of the 
soldering. This is particularly noticeable in electrical work. 

For strength, fit the parts accurately. The more accurate the 
fitting the stronger the result. Use a solder with as high a melting 
point as possible. Apply the proper heat as it should be. The 
nearer the temperature of work to be joined is brought to the fusing 
point of the solder the better will be the union, since the solder will 
flow more readily. 

Fluxes for Different Metals 

There are on the market a number of fluxes or soldering salts 
that are giving good satisfaction. A form that is non-corrosive 
and very popular with electrical workers is the soldering stick in 
which the ingredients are molded into stick form about i inch diam- 
eter and 6 inches long. 

The action and use of a flux in soldering are to remove and pre- 
vent the formation of an oxide during the operation of soldering, 
and to allow the solder to flow readily and to unite more firmly 
with the surfaces to be joined. 

For sheet tin, on the best work rosin or colophony is used; but 
owing to the ease of applying and rapidity of working, zinc chloride 



SOLDERING 87 

or acid is more generally used. Beeswax can also be used, as also 
almost any of the pastes, fats or liquids prepared for the purpose. 

For lead, a flux of oil and rosin in equal parts works very well. 
Tallow is also a good flux. Rosin or colophony is much used, and 
zinc chloride will keep the surfaces in good condition. 

Lead burning is a different operation from soldering, and at the 
present time almost a lost art. The surfaces must be bright and 
free from oxide; solder is not used as a flux, but a piece of lead and 
rosin or oil. 

For brass, zinc chloride or almost any of the soldering prepara- 
tions is used. Care must be taken to remove any scale or oxide 
if a good joint is wanted. On new metal this is not much trouble, 
but on old or repair work it is sometimes exceedingly difficult. This 
is particularly noticeable on metal patterns that have been in use 
for some time. The scraper must be brought into use to remove it. 
Many use with considerable success an acid dip such as is com- 
monly used by electro platers, for removing the oxide. Oily or 
greasy work can be cleaned by the use of potash or lye, but care 
must be exercised that the brass is not left too long in the solution, 
especially if it contains any joints previously soldered, since the 
action set up will dissolve the solder entirely or roughen up the 
joint to such an extent as to require refinishing. 

For copper, the same fluxes as for brass are used. On old work 
it is almost always necessary to scrape the parts to be joined to get 
the solder to hold. A particularly difficult piece of work to solder 
is an old bath tub. The grease and soap form a layer that is imper- 
vious to any of the fluxes, and it must be carefully removed entirely 
if good work is wanted. 

For zinc, use muriatic acid almost full strength or chloride of 
zinc solution. Zinc is the metal that has a "critical temperature" 
more than any other metal except the softer alloys. If the iron is 
overheated, the zinc is melted and a hole burned in the metal; 
even if this does not occur, the surface of the metal is roughened 
and there is formed on the soldering copper an alloy that will not 
flow but simply makes a pasty mass. At the correct heat the solder 
will flow readily and unite firmly with the metal. Especially if 
the work is to be painted, care should be taken to neutraUze and 
wash off any excess of acid or soldering solution, as it is impossible 
to cause paint to adhere properly unless this is done. 

For galvanized iron, use muriatic acid, chloride of zinc solution 
or rosin, and be sure to see that the acid is neutralized if the work 
is to be painted. Many cornices and fronts are made of this metal 
and are very unsightly in a short time after being painted, particu- 
larly at the joints, owing to lack of care in removing the excess flux. 

An action that is not usually taken into consideration in the joining 
of galvanized iron or zinc with copper, as is sometimes done, is the 
electrical action set up by the metals if any moisture is present. 
This is very noticeable in cities where the acid from the atmosphere 
assists in the action. It will nearly always be found that the zine 
or galvanized iron has been greatly injured at the places joined. 

For wrought iron or steel, zinc chloride is best. The iron or steel, 
to make good work, should be previously freed from scale or oxide 



88 SOLDERING 

and tinned before joining. Where the oxide is not very heavy, 
the iron can be cleaned by brushing with muriatic acid and rubbing 
with a piece of zinc. 

The Fluxes Themselves 

The above paragraphs give the fluxes adapted to the various 
metals; the fluxes themselves are as follows: 

Hydrochloric or muriatic acid. The ordinary commercial acid 
is much used in full strength or slightly diluted to solder zinc, par- 
ticularly where the zinc is old or covered with an oxide. 

Rosin or colophony, powdered, is commonly used for copper, tin 
and lead, and very generally by canneries and packing houses on 
account of its non -poisonous qualities. It is also used mixed with 
common olive oil. Turpentine can also be used as a flux. Beeswax 
is a good but expensive flux. Tallow is also used for lead pipe, 
but is more frequently mixed with rosin. 

Palm or cocoa oil will work well, but is more generally used in 
the manufacture of tin plate. The common green oUve oil works 
very well with the more fusible solders. 

As expedients we can use a piece of common stearine candle or 
a piece of common brown rosin soap or cheap furniture varnish, 
which is largely composed of rosin. Paraffin, vaseline and stearine 
are recommended for use with some of the alloys for soldering alu- 
minum. 

Chloride of zinc, acid, or soldering liquid, is the most commonly 
used of all the fluxes; as usually prepared, simply dissolve as much 
scrap zinc in the ordinary commercial muriatic acid as it will take 
up. But if it is diluted with an equal quantity of water and a small 
quantity of sal ammoniac is added it works much better and is less 
likely to rust the articles soldered. If they are of iron or steel, about 
2 ounces to the pint of solution is about the proper quantity of pow- 
dered sal ammoniac to add. 

In preparing this solution, a glass or porcelain vessel should be 
used; owing to the corrosive fumes, it should be done in a well- ven- 
tilated place. Use a vessel of ample capacity, since there is con- 
siderable foaming or boiling of the mixture. 

Soldering liquid, non-corrosive, is also prepared by dissolving 
the zinc in the acid as above and adding one fourth of the quantity 
of aqua ammonia to neutralize the acid, then diluting with an equal 
quantity of water. 

Soldering liquid, neither corrosive nor poisonous. Dissolve ij 
parts glycerin, 12 parts water, and add i\ parts lactic acid. 

Soldering paste. When a solution of chloride is mixed with starch 
paste, a syrupy Hquid is formed which makes a flux for soldering. 

Soldering fat or paste. Melt i pound of tallow and add I pound 
of common olive oil. Stir in 8 ounces of powdered rosin; let this 
boil up and when partially cool, add with constant stirring, \ pint 
of water that has been saturated with powdered sal ammoniac. 
Stir constantly until cool. By adding more rosin to make it harder, 
this can be formed into sticks. A very good acid mixture for clean- 
ing work to be soldered is equal parts of nitric and sulphuric acid 
and water. Never pour the water into the acid. 



SOLDERING CAST IRON 



Cleaning and Holding Work 



89 



For copper work a dilute sulphuric acid is best. Articles of lead 
and zinc can be cleaned with a potash solution, but care must be 
exercised as the alkalies attack these metals. For zinc, a dilute 
solution of sulphuric or muriatic acid will clean the surface. 

For cleaning or removing the oxide or other foreign material, 
scrapers and files are frequently used. An old file bent at the ends 
and with the comers flaring makes a handy tool. Grind the edge 
sharp and make as hard as possible. 

To enable difficult points to be "filled," sometimes a small piece 
of moist clay pressed into shape to form the desired shape can be 
used to advantage as a guide for the solder. Another use of the 
clay is to embed the parts in, to hold them in position for soldering. 

Plaster of paris is also used for this purpose, but is sometimes 
difiicult to remove, especially in hollow pieces. A dilute solution 
of muriatic acid will help to get this out, however. 

Castings containing aluminum are always harder to solder than 
other alloys. In some instances where the percentage of aluminum 
is high, it is necessary to copperplate the parts to be joined before 
a satisfactory joint can be made. In nearly every instance the work 
can be "stuck" together, but not actually soldered. 

In metal-pattern making too little attention is given to both the 
fitting of the parts and the selection of the solder to joint the work. 
A good grade should always be used, and it must be borne in mind 
that the higher the melting point of the solder the stronger the joint. 

A very good job of soldering can be done on work that will permit 
of it by carefully fitting the parts, laying a piece of tin foil, covered 
on both sides with a flux, between the parts to be joined and pressing 
them tightly together. Heat until the foil is melted. This is very 
good in joining broken parts of brass and bronze work. If they 
fit well together, they can frequently be joined in this manner so 
that the joint is very strong and almost imperceptible. 

Soldering Cast Iron 

For cast iron, the flux is usually regarded as a secret. A number 
of methods are in use; one of the oldest and least satisfactory is to 
brush the surfaces thoroughly with a brass scratch brush. Brush 
until the surface is coated with brass, then tin this surface and solder 
as usual. If plating facilities are to be had, copperplate the parts 
and solder together. This method has been used very successfully 
for a number of years. 

A fair substitute for the above is to clean the surfaces thoroughly 
and copperplate them with a solution of sulphate of copper: about 
I ounce sulphate of copper, \ pint water, ^ ounce sulphuric acid. 
Brush this solution on or dip into the solution, rinse off and dry it 
well before soldering. 

Another method is to tin the cast iron. To do this, first remove 
all scale until the surface is clean and bright. The easiest way to 
do this is with the emery wheel. Dip in a lye to remove any grease, 
and rinse the lye off; then dip into muriatic acid of the usual strength. 



90 SOLDERING 

Then go over the surface with rosin and a half and half solder. It 
may be necessary to dip into the acid several times to get the piece 
thoroughly tinned. Rubbing the surface of the iron with a piece 
of zinc while the acid is still on it will facilitate the tinning. 

Another method of soldering cast iron is to clean the surface as 
in the previous operation and then brush over with chloride of zinc 
solution and sprinkle powdered sal ammoniac on it; then heat until 
the sal ammoniac smokes. Dip into melted tin and remove the 
surplus; repeat if not thoroughly tinned. Half tin and half lead 
works well as a solder for this. 

Commutator wires and electrical connections should never be sol- 
dered by using an acid solution, owing to the corrosive action after- 
ward. A good flux is an alcoholic solution of rosin. 



Cold Soldering for Metals, Glass, Porcelain, etc. 

Precipitate the copper froiji a solution of the sulphate by putting 
in strips of zinc. Place the copper powder in a porcelain or wedge- 
wood mortar and mix it with from 20 to 30 parts of sulphuric acid 
of 1.85 degrees Baume. Then add 70 parts of mercury when well 
mixed, wash well with water to remove the excess of acid and allow 
it to cool. To use it, heat it and pound it well in an iron mortar 
until it becomes plastic. It can then be used and adheres very firmly 
when cold. No flux is needed, but the surfaces must be clean. This 
is used where heat cannot be used, or to join metal parts to glass or 
porcelain. 

A solution of copper for copperplating steel or cast iron before 
soldering will work by simply immersing the work in it. This is 
also useful to copper the surface of dies and tools to enable the me- 
chanic to "lay out" or scribe the work so that the lines can be readily 
seen. Take copper sulphate 3I ounces, sulphuric acid 3^ ounces, 
water i to 2 gallons. Dissolve the copper in the water and add the 
acid. 

Solders and Fusible Alloys 

Solders act under constant stress considerably like plastic or semi- 
fluid material. Their fluidity resembles that of tar or gum, and their 
distortion with time is greater than would be thought. In a series 
of tests a notable point brought out was the varying degrees of 
strength with age. Tensile strength increases with the percentage of 
tin present, but when the solder's age is considered as a factor, the 
product possesses its maximum value at 60 per cent, tin, showing this 
property as similar to that of the melting point and depending upon 
chemical composition. 

For general work, the solder requiring resistance to stress is 60 
per cent, tin, but for work requiring little mechanical strength, such 
as sealing, a lower per cent, of tin may be used. 

Generally speaking, all solders are alloys of lead and tin. The more 
lead the alloy contains, above 40 per cent., the higher is its melting 
point, as also the less lead it contains, below 40 per cent., the lower 
is its melting point. 



SOLDERING 



91 



The melting point of alloys which fuse at a low temperature may 
be found by tying a small wire around a fragment of alloy and hang- 
ing it in a bath of water. A thermometer should be kept in the bath 
and the temperature increased slowly until the alloy melts. The melt- 
ing point of the alloy can then be noted by the temperature of the 
bath. For higher temperature a bath of paraffin or oil is used. If 
bismuth is added to these alloys the melting point is lower, as bismuth 
possesses the quality of expanding on cooling, a property which is 
very unusual in metals. Bismuth is used not only to make the alloy 
or solder more easily worked, by diminishing its melting point, but 
if sufficient quantity be present its expansive tendency counter- 
balances the effects of the contraction of the other metals, and the 
total result is the prevention or reduction of shrinkage in the mold. 
The addition of cadmium still farther lowers the melting point of such 
alloys as those of bismuth, lead and tin, which in themselves have 
very low melting points. 

Composition and Melting Point of Solders and Fusible 
Alloys 



Alloy 


Lead 


Tin 


Bis- 
muth 


Other 
Constitu- 
ents 


Melting Point 


Cent. 


Fahr. 


Solder i 


96.15 

90.9 

83.3 

75-0 

66.7 

50.0 

40.0 

33-3 

33-3 

48.4 

44.5 
42.1 
10. 
30.0 

31-25 

28.1 

25.0 

25.0 

26.9 

66.7 


3-85 

9.1 
16.7 

25-9 
33-3 
50.0 
60.0 
66.7 
33-3 

40.0 
20.0 

18.75 

21.9 

25.0 

12.5 

12.7 


33-3 
12.8 
22.2 
42.1 
50.0 
50.0 
50.0 
50.0 
50.0 
50.0 
50.0 
8.3 


Zinc 
38.8 
33-3 
15-8 

Cadmium 

12. 5 
10.4 
25.0 


292 

283 

266 

250 

227 

188 

168 

171 

140 

171 

141 

123 

116 

100 

98 

95 

93 

60 

66 

66 


558 


Solder 2 


')4I 


Solder 3 


511 
482 


Solder 4 


Solder 5 

Solder 6 


441 

370 


Solder 7 


334 


Solder 8 


340 


Solder g 


284 


1. Steam boiler plug 

2. Steam boiler plug . 

3. Steam boiler plug . 

4. Steam boiler plug . 
Sir Isaac Newton's. 
Suitable for casts . 

Rose's alloy 

D'Arcet's alloy . . . 

Wood's alloy 

Lipowitz's alloy . . 
Expanding alloy . . 


340 
285 
253 
240 
212 
208 
203 
200 
140 
150 
150 



Hard solders sometimes contain more or less copper. A substan- 
tial solder contains 60 per cent, copper, 20 per cent, tin and 20 per 
cent. zinc. An easily melted yellow, hard solder contains about 45 
per cent, copper and 55 per cent. zinc. This solder is really a brass, 
but at times is used for soldering, binding and filling purposes. 



92 SOLDERING 

Nearly all aluminum solders are alloys of tin and aluminum that 
contain from 15 to 25 per cent, aluminum. A small per cent, of cop- 
per or nickel, never exceeding 2 or 3 per cent., is sometimes used. 
The exact point of separation between a fusible metal and a non- 
fusible one is very uncertain, thus several additional alloys are given 
in the table. In filling up imperfections in ornamental castings for 
plugs in electrical wiring and on boilers in engineering work, fusible 
alloys are used. Sometimes defects in structural steel have been 
filled in with expanding alloy, after being dressed in a coat of point. 
The United States Government rules call for pure Banca tin for boiler 
plugs, but this is not essential and an}- good tin will serve the purpose. 

Experiments have been made in an engineering college quite recently 
for the purpose of finding the way of making solder joints, as well as 
measuring their tensile strength. Any pressure upon the solder at 
the moment of setting diminishes the strength of the joint. Thus, in 
making a solder joint, the upper piece should be held above the lower 
one, the solder fused by means of two blow torches, and the pieces 
brought together by very slow and easy pressure. By employing this 
method, which differs from that commonly called "sweating," the 
joint is less liable to be broken, as the crystalline composition of 
the resulting mass contains less resistance at this time. 

In addition it is found that there is remarkable variation with time 
of the tensile strength of such joints, which is also in accord with 
what would be considered proper by engineering science in this field. 
Under any circumstances the average strength attained does not 
exceed 27,000 pounds per square inch, and was obtained from solder 
made with three-fifths of its composition tin. 

ARSENAL "HOT DLP" PROCESS FOR TINNING 

Use a metal composed of 80 parts of lead to 20 parts of tin by 
weight. The steel plate to be tinned is first pickled in a bath of 
40 parts of water to one part of sulphuric acid by volume. After 
pickling, the metal is washed in clean water to remove all traces 
of the pickling acid. The work is then dipped in a flux which is 
made b}'' dissolving zinc in hydrochloric acid until it is saturated. 
After dipping in the flux, the pieces are dipped in the melted metal 
(80% lead — 20% tin) until thoroughly coated and are then 
shaken off and thrown in a pile to cool. 

A Method of Tinning Brass Parts 

Brass parts are placed in layers in a screened basket with tin 
plates between each layer. They are then placed in a copper tank 
filled with water supplied wnth steam coil and brought to a boiling 
point. Sufficient amount of Cream of Tartar is added until the 
parts are properly plated. Four hours are required to properly 
tin these parts. 

Small parts are placed in a cheese cloth bag in a solution of one 
pint of phosphoric acid (U.S.P. 50% ) to four gallons of water. Heat 
to a boiling point until pins begin to turn white, requiring about 
two hours. Remove and place in linseed oil. They are then 
rolled on staw boards to remove the surplus oil. 



GEARING 



GEAR TEETH — SHAPES OF 

Cycloidal or Epicycloidal. — A curved tooth generated by the point 
of a circle rolling away from the gear wheel or rack. 

Involute. — A curved tooth generated by unwinding a tape or 
string from a cylinder. The rack tooth has straight sides. 

Involute Standard. — The standard gear tooth has a 14^ degree 
pressure angle which means that the teeth of a standard rack have 
straight sides 14J degrees from the vertical. 

Involute — Stubbed. — A tooth shorter than the standard and 
usually with a 20-degree pressure angle. 




GEARS— TEETH AND PARTS 

^ t<^ CireuJar 




I I 
1- * Measured on tho Ktch Circle 

Fig. I. — Part of Gear Teeth 



Addendum. — Length from pitch line to outside. 

Chordal Pitch. — Distance from center to center of teeth in a 
straight line. 

Circular Pitch. — Distance from center to center of teeth meas- 
ured on the pitch circle. 

Clearance. — Extra depth of space between teeth. 

Dedendum. — Length from pitch line to base of tooth. 

Diametral Pitch. — Number of teeth divided by the pitch diam- 
eter or the treth to each inch of diameter. 

Face. — Working surface of tooth outside of pitch line. 

Flank. • — Working surface of tooth below pitch line. 

Outside Diameter. — Total diameter over teeth. 

Pitch Diameter. — Diameter at the pitch line. 

Pitch Line. — Line of contact of two cylinders which would have 
the same speed ratios as the gears. 

Linear Pitch. — Sometimes used in rack measurement. Same as 
circular pitch of a gear. 

S3 



94 



CIRCULAR PITCH 



Having 

The Diametral , 
Pitch I 

The Pitch Di-1 
ameter and I 
the Number [ 
of Teeth ... J 

The Outside 1 
Diameter and I 
the Number [ 
of Teeth ... J 

The Number 1 
of Teeth and I 
the Circular | 
Pitch J 

The Number ] 
of Teeth and ( 
the Outside | 
Diameter ... J 

The Outside ] 
Diameter and I 
the Circular | 
Pitch J 

Addendum and"] 
the Number [ 
of Teeth ... J 

The Number ] 
of Teeth and I 
the Circular [ 
Pitch J 

The Pitch Di-I 

ameter and I 
the Circular [ 
Pitch J 

The Number 1 
of Teeth and I 
the Adden- | 
dum J 

The Pitch Di-l 
ameter and I 
the Circular | 
Pitch J 

The Circular ) 
Pitch > 

The Circular ) 
Pitch 5 

The Circular ) 
Pitch ) 

The Circular ) 
Pitch i 

The Circular 1 
Pitch 5 

The Circular ) 
Pitch 5 

Thickness of \ 
Tooth ' 



To Get 



The Circular 
Pitch 



The Circular 
Pitch 



The Circular 
Pitch 



Pitch Diameter 



Pitch Diameter 



Pitch Diameter 



Pitch Diameter 



Outside Diameter 



Outside Diameter 



Outside Diameter 



Number of Teeth 



Thickness of 
Tooth 



Addendum 

Root 

Working Depth 

Whole Depth 

Clearance 

Clearance 



Rule 



Di\'ide 3.1416 by the Di 
ametral Pitch . . . 



Divide Pitch Diameter by 
the product of .3183 and 
Number of Teeth 



Divide Outside Diameter by 
the product of .3183 and 
Number of Teeth plus 2 

The continued product of 
the Number of Teeth, the 
Circular Pitch and .3183 

DiNade the product of Num- 
ber of Teeth and Outside 
Diameter by Number of 
Teeth plus 2 

Subtract from the Outside 
Diameter the product of 
the Circular Pitch and 
.6366 



Multiply the Number of 
Teeth by the Addendum 

The continued product of 
the Number of Teeth plus 
2. the Circular Pitch and 
•3183 



Add to the Pitch Diameter 
the product of the Cir 
cular Pitch and .6366. . . 



Multiply Addendum by 
Number of Teeth plus 2 



Divide the product of Pitch 
Diameter and 3.1416 by 
the Circular Pitch 

One half the Circular Pitch 

Multiply the Circular Pitch 
D' 
by .3183 or 5 = — 

Multiply the Circular Pitch 
by .3683 

Multiply the Circular Pitch 
by .6366 

Multiply the Circular Pitch 
by .6866 

Mutliply "the Circular Pitch 
by .05 

One tenth the Thickness of 
Tooth at Pitch Line . . . 



Formula 



F 



.3183 N 



.3183 iV+ 2 
P'=iVP'.3i83 

N+2 

D'=D~ 



iP'.6366] 



D'=Ns 



D=(N+2) 
P' .3183 



D =D'+ 
(i".6366) 



D==s(N+2) 



N 



-P'3-i4i6 



,=^ 



s-P-. iiS} 



s+f= 


P' .3683 


D"=P 


.6366 


D"=P 


.6866 


f = P' 


•05 


f-\ 





DIAMETRAL PITCH 



95 



Having 

The Circular 
Pitch 

The Pitch Di- 
ameter and 
the Number 
of Teeth . . . 

The Outside 
Diameter and 
the Number 
of Teeth 

The Number of 
Teeth and 
the Diametral 
Pitch 

The Number of 
Teeth and the 
Outside Di- 
ameter 

The Outside 
Diameter and 
the Diame- 
tral Pitch . . . , 

Addendum and 
the Number 
of Teeth ... ^ 

The Number of 
Teeth and the 
D iametral 
Pitch 

ThePitchDiam-" 
eter and the 
Diametral 
Pitch , 

The Pitch Di- 
ameter and 
the Number 
of Teeth . . . 

The Number of ] 
Teeth and 
Addendum . . 

The Pitch Di- 
ameter and 
the Diametral 
Pitch 

The Outside ' 
Diameter and 
the Diametral 
Pitch 

The Diametral 
Pitch 

The Diametral 
Pitch 

The Diametral 

Pitch 

The Diametral 

Pitch 

The Diametral 

Pitch 

The Diametral 

Pitch 

Thickness of i 

Tooth 



To Get 



The Diametral 
Pitch 



The Diametral 
Pitch 



The Diametral 
Pitch 



Pitch Diameter 

Pitch Diameter 

Pitch Diameter 

Pitch Diameter 

Outside Diameter 

Outside Diameter 

Outside Diameter 
Outside Diameter 



Number of 
Teeth 



Number of 
Teeth 

Thickness of 
Tooth 

Addendum 

Root 

Working Depth 

Whole Depth 

Clearance 

Clearance 



Rule 



Divide 3.1416 by the Cir 
cular Pitch , 



Divide Number of Teeth by 
Pitch Diameter 



Divide Number of Teeth 
plus 2 by Outside Di 
ameter 



Divide Number of Teeth by 
the Diametral Pitch . . 



Divide the Product of Out 
side Diameter and Num 
ber of Teeth by Number 
of Teeth plus 2 

Subtract from the Outside 
Diameter the quotient of 
2 divided by the Diametral 
Pitch 



Multiply Addendum by the^ 
Number of Teeth 



Formula 



3-1416 



N 



P = 



N+2 



D'-- 



DN 



Divide Number of Teeth 
plus 2 by the Diametral 
Pitch 



Add to the Pitch Diameter 
the quotient of 2 divided 
by the Diametral Pitch 

Divide the Number of Teeth 
plus 2, by the quotient of 
number of Teeth divided 
by Pitch Diameter . . . 

Multiply the Number of 
Teeth plus 2 by Adden 
dum 



Multiply Pitch Diameter by 
the Diametral Pitch . . 



Multiply Outside Diameter 
by the Diametral Pitch 
and subtract 2 



Divide 1.5708 by the Di 

ametral Pitch 

Divide i by the Diametral 

Pitch or J = TV 

N 

Divide 1.157 by the Diam- 
etral Pitch 

Divide 2 by the Diametral 
Pitch 

Divide 2.157 by the Dia- 
metral Pitch 

Divide .157 by the Diametral 
Pitch 

Divide Thickness of Tooth 
at pitch hne by 10 



N+2 

iy=sN 



D=D' 



D = 



P 

N+2 

N 
D' 



D=(N+2)s 
N==D' P 

N==DP-2 

, 1-5708 
^ - P 

I 



B"=i 



D"+f 
f 



2-157 
P 



f 



iL17 

P 

t 



96 GEARING 

Table of Corresponding Diametral and Circular Pitches 



Table No. i 


Table No. 2 


Diametral 
Pitch 


Circular Pitch 


Circular 
Pitch 


Diametral Pitch 


li 


2-5133 


2 


I-57I 


I^ 


2.0944 


i| 


1.676 


if 


1-7952 


If 


1-795 


2 


I-57I 


If 


1-933 


2i 


1.396 


li 


2.094 


2i 


1-257 


ItV 


2.185 


2| 


1. 142 


'K 


2.285 


3 


1.047 


lA 


2.394 


3^ 


.898 


li 


2-513 


4 


.7S5 


lA 


2.646 


5 


.628 


i| 


2-793 


6 


.524 


ItV 


2.957 


7 


.449 


I 


3.142 


8 


.393 


if 


3-351 


9 


•349 


1 


3-590 


lO 


.314 


if 


3.867 


II 


.286 


f 


4.189 


12 


.262 


16 


4-570 


14 


.224 


f 


5.027 


i6 


.196 


T^. 


5-585 


i8 


•175 


i 


6.283 


20 


.157 


tV 


7. 181 


22 


.143 


t 


8.378 


24 


•131 


t\ 


10-053 


26 


.121 


i 


12.566 


28 


.112 


^ 


16.755 


30 


.105 


i 


25-133 


32 


.098 


tV 


50.266 


36 


.087 






40 


.079 






48 


.065 







No. I table shows the diametral pitches with the corresponding 
circular pitches. 

No. 2 table shows the circular pitches with the corresponding 
diametral pitches. 

It is most natui'al to think of gears in circular or linear pitch and 
we soon get to know the size of any pitch, as 12, as being a little 
over i inch from center to center. But the diametral system has 
many advantages in figuring gear blanks, center distances, etc. 

The Center Distance of any pair of spur gears is found by adding 
one-half the pitch diameter of both gears. 



CONSTANTS FOR CHORD AL PITCH 



97 



Constant for any number of teeth 



CONSTANTS FOR DETERMINING CHORDAL PITCH AND 
RADIUS OF SPUR GEARS 

P = Chordal Pitch of Teeth. 

R = Radius of Pitch Circle. 

N = Number of Teeth. 

C = Constant. (See table below.) 

_, , , . , Radius of pitch circle 

Chordal pitch = — \ ;: r. 

Constant tor number oi teeth 

Radius of pitch circle = Constant X chordal pitch. 

Radius of pitch circle 

Chordal pitch of teeth* 

Examples : i . What is radius of pitch circle of a gear having 45 teeth, 

if inch pitch? Follow 40 in table to column 5 (making 45 teeth), 

and find 7.168. Multiply by pitch, if inch, and get 12.54 inches 

radius or 25.08 pitch diameter. 

2. What is the chordal pitch of a gear 32 inches pitch diameter, 
67 teeth? Follow 60 in table to column 7 and find 10.668. Divide 
radius (| of 32 = 16 inches) by constant. 16 ^ 10.668 = 1.5 inch 
pitch. 

3. What number of teeth has a gear of 1.5 inch chordal pitch and 
pitch diameter 32 inches? Divide by 2 to get radius. Divide this 
by chordal pitch which will give constant. 16-7- 1.5 = 10.666. Look 
in table for this constant which will be found to represent 67 teeth. 

Table of Constants 



N 





I 


2 


3 


4 


5 


6 


7 


8 


9 





0.000 


0.000 


0.500 


0.577 


0.707 


0.851 


1. 000 


1. 152 


1-307 


1.462 


10 


1.618 


1.774 


1.932 


2.089 


2.247 


2.405 


2-563 


2.721 


2.879 


3-038 


20 


3.196 


3.355 


3-513 


3.672 


3.831 


3.989 


4.148 


4-307 


4-465 


4.624 


30 


4.783 


4.942 


5.101 


5.260 


5.419 


5.578 


5-737 


5.896 


6.055 


6.214 


40 


6.373 


6.532 


6.691 


6.850 


7.009 


7.168 


7-327 


7.486 


7.645 


7.804 


50 


7-963 


8.122 


8.281 


8.440 


8.599 


8.758 


8.918 


9.077 


9.236 


9-395 


60 


9-554 


9.713 


9.872 


10.031 


10.190 


10.349 


10.508 


10.668 


10.827 


10.986 


70 


II. 145 


IX. 304 


11.463 


11.622 


II. 781 


11.940 


12.099 


12.258 


12.418 


12.577 


80 


12.736 


12.895 


13.054 


13.213 


13.372 


13-531 


13.690 


13.849 


14.008 


14.168 


90 


14-327 


14-486 14.645 


14.804 


14.963 


IS-123 


15.282 


15-441 


15.600 


15-759 


100 


15-918 


16.077 


16.236 


16.395 


16.554 


16.713 


16.873 


17-032 


17.191 


17.350 


no 


17-509 


17-668 


17.828 


17.987 


18.146 


18.305 


18.464 


18.624 


18.783 


18.942 


120 


19.101 


19.260 


19.419 


19-579 


19-738 


19.897 


20.056 


20.215 


20.375 


20.534 


130 


20.693 


20.852 


2 1. 01 1 


21.170 


21.330 


21.489 


21.648 


21.807 


21.966 


22.126 


140 


22.285 


22.444 


22.603 


22.762 


22.921 


23.081 


23.240 


23-399 


23-558 


23.717 


150 


23-877 


24.036 


24.195 


24-354 


24-513 


24.672 


24.832 


24.991 


25-150 


25.309 


160 


25.468 


25.627 


25-787 


25-946 


26.105 


26.264 


26.423 


26.583 


26.742 


26.901 


170 


27.060 


27.219 


27-378 


27-538 


27.697 


27.856 


28.015 


28.174 


28.334 


28.493 


180 


28.652 


28.811 


28.970 


29.129 


29.289 


29.448 


29.607 


29.766 


29.925 


30.085 


190 


30-242 


30.403 


30.562 


30.721 


30.880 


31.040 


31-199 


31-358 


31-517 


31-676 


200 


31-830 


31.9S9 


32-148 


32.307 


32.446 


32-625 


32.785 


32.944 


33-103 


33-262 


210 


33-427 


33-586 


33-746 


33-905 


34.064 


34-223 


34.382 


34-542 


34.701 


34-860 


220 


35-019 


35-178 


35-337 


35-497 


35-656 


35-815 


35-974 


36.133 


36-293 


36-452 


230 


36.611 


36.770 


36.929 


37.088 


37-248 


37-407 


37-566 


37-725 


37-884 


38.044 


240 


38.203 


38.362 


38.521 


38.680 


38-839 


38-999 


39-158 


39-317 


39-476 


39635 


250 


39.7C5 





















98 



GEARING 



Gear Wheels 
table of tooth parts diametral pitch in 



[RST COLUMN 







'^'t 


*Mla, 


•^ 


^.2 


"o 


f 


•§ 


"S 


1 






^ 


13 


S 


1% 




Q 


'oS 


a 


1^ 


I3j 


Msi 


"2 


^■B 


^ 


6 


6 






1 




M 
&2 


¥ 


s 


u 


H 


< 


^ 


Q 


^ 


p 


P' 


t 


s 


D" 


H-/ 


D"+/ 


h 


6.2832 


3.1416 


2.0000 


4.0000 


2.3142 


4.3142 


f 


4.1888 


2.0944 


T-?>m 


2.6666 


1.5428 


2.8761 


I 


3.I4I6 


1.5708 


1. 0000 


2.0000 


I-1571 


2.1571 


li 


2-5133 


1.2566 


.8000 


1.6000 


-9257 


1-7257 


li 


2.0944 


1.0472 


.6666 


^■?>3?>3 


•7714 


1-4381 


If 


1-7952 


.8976 


•5714 


1. 1429 


.6612 


1.2326 


2 


1.5708 


•7854 


.5000 


1. 0000 


.5785 


1.0785 


2i 


1-3963 


.6981 


-4444 


.8888 


.5143 


.9587 


2h 


1.2566 


.6283 


.4000 


.8000 


.4628 


.8628 


2\ 


1. 1424 


•5712 


.3636 


-7273 


.4208 


•7844 


3 


1.0472 


-5236 


•3333 


.6666 


-3857 


.7190 


?>h 


.8976 


.4488 


.2857 


-5714 


•3306 


.6163 


4 


.7854 


-3927 


.2500 


.5000 


.2893 


•5393 


5 


.6283 


.3142 


.2000 


.4000 


.2314 


-4314 


6 


•5236 


.2618 


.1666 


■33,?,i 


.1928 


-3595 


7 


.4488 


.2244 


.1429 


.2857 


•1653 


.3081 


8 


-3927 


.1963 


.1250 


.2500 


.1446 


.2696 


9 


-3491 


-1745 


.iiii 


.2222 


.1286 


•2397 


lO 


-3142 


-1571 


.1000 


.2000 


•I157 


•2157 


II 


.2856 


.1428 


.0909 


.1818 


.1052 


.1961 


12 


.2618 


.1309 


•0833 


.1666 


.0964 


.1798 


13 


.2417 


.1208 


.0769 


•1538 


.0890 


.1659 


14 


.2244 


.1122 


.0714 


.1429 


.0826 


• 1541 



To obtain the size of any part of a diametral pitch not given in the 
table, divide the corresponding part of i diametral pitch by the pitch 
required. 



As it is natural to think of gear pitches as the distance between 
teeth the same as threads, it is well to fix in the mind the approxi- 
mate center distances of the pitches most in use. Or it is easy to 
remember that if the diametral pitch be divided by 3I we have the 
teeth per inch on the pitch line. By this method we easily see that 
in a 10 diametral pitch gear there are approximately 3 teeth per inch 
while in a 22 diametral pitch there will be just 7 teeth to the inch. 



PARTS OF TEETH 



99 



Table of Tooth Parts — Continued 

DIAMETRAL PITCH IN FIRST COLUMN 







■^-s 


*Hla. 


*o 


8S 


'o 


1 




<u a 
a ° 


1 

1 










!3 


^^ 


T3 


^:S 


^ 


ji 


a 

.2 


-^ 
3 

.^ 




a 


1^ 


M 

&2 





Q 





H 


^ 


^ 


Q 


^ 


P 


P' 


/ 


s 


D" 


s+f 


D"+f 


15 


2094 


.1047 


.0666 


•1333 


.0771 


.1438 


t6 


1963 


.0982 


.0625 


.1250 


.0723 


.1348 


17 


1848 


.0924 


.0588 


.1176 


.0681 


.1269 


i8 


1745 


.0873 


•0555 


.1111 


.0643 


.1198 


19 


1653 


.0827 


.0526 


•1053 


.0609 


.1135 


20 


1571 


.0785 


.0500 


.1000 


•0579 


.1079 


22 


1428 


.0714 


•0455 


.0909 


.0526 


.0980 


24 


1309 


.0654 


.0417 


•0833 


.0482 


.0898 


26 


1208 


.0604 


•0385 


.0769 


•0445 


.0829 


28 


1122 


.0561 


•0357 


.0714 


■0413 


.0770 


30 


1047 


.0524 


•0333 


.0666 


.0386 


.0719 


32 


0982 


.0491 


.0312 


.0625 


.0362 


.0674 


34 


0924 


.0462 


.0294 


.0588 


.0340 


.0634 


36 


0873 


.0436 


.0278 


•0555 


.0321 


•0599 


38 


0827 


.0413 


.0263 


.0526 


.0304 


.0568 


40 


0785 


.0393 


.0250 


.0500 


.0289 


•0539 


42 


0748 


•0374 


.0238 


.0476 


.0275 


.0514 


44 


0714 


•0357 


.0227 


•0455 


.0263 


.0490 


46 


0683 


.0341 


.0217 


•0435 


.0252 


.0469 


48 


0654 


.0327 


.0208 


.0417 


.0241 


.0449 


50 


0628 


.0314 


.0200 


.0400 


.0231 


.0431 


56 


0561 


.0280 


.0178 


•0357 


.0207 


.0385 


60 


0524 


.0262 


.0166 


•0333 


.0193 


.0360 



To obtain the size of any part of a diametral pitch not given in the 
table, divide the corresponding part of i diametral pitch by the pitch 
required. 



As it is natural to think of gear pitches as the distance between 
teeth the same as threads, it is well to fix in the mind the approxi- 
mate center distances of the pitches most in use. Or it is easy to 
remember that if the diametral pitch be divided by 3y we have the 
teeth per inch on the pitch line. By this method we easily see that 
in a 10 diametral pitch gear there are approximately 3 teeth per inch 
while in a 22 diametral pitch there will be just 7 teeth to the inch. 



100 



GEARING 



Gear Wheels 
table of tooth parts — circular pitch in first column 



I^H 




"o-u 


-0 


^ 


8S 


"o 


-T3 


T3 


3 




43 




i-i 






.5 
-18 


■5'S 


5h° 




1^ 


Q 




r 


P 


r 


1 


S"^ 


r 


P' 




p 


/ 


s 


D" 


s+f 


D"+/ 


P'X.31 


p'x.335 


2 


^ 


1.5708 


1. 0000 


.6366 


1.2732 


.7366 


1-3732 


.6200 


.6700 


If 


tV 


1-6755 


•9375 


.5968 


1^1937 


.6906 


1.2874 


.5813 


.6281 


If 


f 


1-7952 


.8750 


•5570 


1.1141 


•6445 


1. 2016 


-5425 


•5863 


If 


? 


1-9333 


.8125 


-5173 


1-0345 


.5985 


1.1158 


.5038 


•5444 


I^ 


f 


2.0944 


.7500 


-4775 


.9549 


•5525 


1.0299 


.4650 


•5025 


itV 


if 


2-1855 


.7187 


•4576 


•9151 


-5294 


.9870 


•4456 


.4816 


if 


tV 


2.2848 


•6875 


-4377 


.8754 


•5064 


.9441 


.4262 


.4606 


li 


1 


2.3562 


.6666 


.4244 


.8488 


.4910 


•9154 


•4133 


.4466 


It\ 


M 


2-3936 


.6562 


.4178 


.8356 


•4834 


.9012 


.4069 


•4397 


li 


t 


2.5133 


.6250 


-3979 


.7958 


.4604 


•8583 


•3875 


.4188 


ixV 


if 


2.6456 


.5937 


•3780 


•7560 


.4374 


.8156 


.3681 


-3978 


li 


f 


2.7925 


•5625 


•3581 


.7162 


.4143 


•7724 


.3488 


•3769 


ItV 


if 


2.9568 


.5312 


.3382 


.6764 


•3913 


.7295 


•3294 


•3559 


I 


I 


3-1416 


,5000 


•3183 


.6366 


•3683 


.6866 


.3100 


•3350 


H 


itV 


3-3510 


-4687 


.2984 


.5968 


•3453 


•6437 


.2906 


.3141 


i 


li 


3-5904 


•4375 


•2785 


.5570 


.3223 


.6007 


.2713 


•2931 


if 


ItV 


3.8666 


.4062 


.2586 


•5173 


•2993 


•5579 


.2519 


.2722 


f 


li 


3-9270 


.4000 


•2546 


.5092 


.2946 


•5492 


.2480 


.2680 


1 


I* 


4.1888 


-3750 


•2387 


.4775 


.2762 


•5150 


•2325 


•2513 


? 


^p 


4-5696 


•3437 


.2189 


•4377 


•2532 


.4720 


.2131 


•2303 


f 


l\ 


4.7124 


■2,333 


.2122 


.4244 


•2455 


.4577 


.2066 


•2233 


1 


If 


5-0265 


-3125 


.1989 


.3979 


.2301 


.4291 


.1938 


.2094 


1 


tS 


5-2360 


.3000 


.1910 


.3820 


.2210 


.4120 


.i860 


.2010 


f 


If 


5-4978 


•2857 


.1819 


•3638 


.2105 


•3923 


.1771 


.1914 


t\ 


ll 


5-5851 


.2812 


.1790 


.3581 


.2071 


.3862 


.1744 


.1884 



To obtain the size of any part of a circular pitch not given in the 
table, multiply the corresponding part of i" pitch by the pitch re- 
quired. 



As an example take a gear having 21 diametral pitch to find the 
various tooth parts. Take i diametral pitch and divide 3.1416 by 
21 to find the corresponding circular pitch, which is .14951. The 
tooth thickness is 1.5708 -^ 21 = .748; the addendum is i.-r- 21 = 
©4761; the working depth is 2.-f- 21. = .09522; the depth below 



PARTS OF TEETH 



lOI 



Table of Tooth Parts 
circular pitch in first column 





^!5 




"^•3 


T3 


M 


S§ 


•0 


"U 


T) 


3 


^1 


e 

.3 




a 

h 


ft 

w 

1,8 




0, 
■^1 




1^ 


u 


h"^ 


Q 


H 


s 


^ 


Q 


^' 


^ 


P' 




P 


/ 


D" 


^4-/ 


D"+f 


p'x.31 


P'X.335 


h 


2 


6.2832 


.2500 


-1592 


.3183 


.1842 


.3433 


.1550 


-167s 


1 


2i 


7.0685 


.2222 


•I4I5 


.2830 


•1637 


•3052 


•1378 


.1489 


tV 


2f 


7.1808 


.2187 


-1393 


-2785 


.1611 


.3003 


.1356 


.1466 


f 


2* 


7-3304 


.2143 


-1364 


.2728 


-1578 


.2942 


.1328 


.1436 


f 


2i 


7.8540 


,2000 


•1273 


-2546 


-1473 


.2746 


.1240 


.1340 


f 


2§ 


8.3776 


-1875 


.1194 


-2387 


.1381 


•2575 


.1163 


.1256 


t\ 


2| 


8.6394 


.1818 


.1158 


-2316 


.1340 


.2498 


.1127 


.1218 


i 


3 


9.4248 


.1666 


.1061 


.2122 


.1228 


.2289 


.1033 


.1117 


¥ 


3i 


10.0531 


.1562 


-0995 


.1989 


.1151 


,2146 


.0969 


.1047 


1^ 


3i 


10.4719 


.1500 


-0955 


.1910 


.1105 


.2060 


-0930 


.1005 


f 


3^ 


10.9956 


.1429 


.0909 


.1819 


.1052 


.1962 


.0886 


-0957 


i 


4 


12.5664 


.1250 


.0796 


•1591 


.0921 


.1716 


-0775 


.0838 


f 


4^ 


14.1372 


.1111 


.0707 


•1415 


.0818 


.1526 


.0689 


-0744 


t 


5, 


15.7080 


.1000 


-0637 


-1273 


•0737 


•1373 


.0620 


.0670 


♦ 


5i 


16.7552 


•0937 


-0597 


.1194 


.0690 


.1287 


•0581 


.0628 


A 


5i 


17.2788 


.0909 


-0579 


.1158 


.0670 


.1249 


.0564 


.0609 


\ 


6 


18.8496 


•0833 


-0531 


.1061 


.0614 


.1144 


•0517 


-0558 


^? 


6i 


20.4203 


.0769 


.0489 


.0978 


.0566 


-1055 


-0477 


-0515 


\ 


7 


21.9911 


.0714 


-0455 


.0910 


.0526 


.0981 


-0443 


-0479 


^-E 


lh 


23.5619 


.0666 


•0425 


.0850 


.0492 


.0917 


.0414 


.0446 


\ 


8 


25-1327 


.0625 


•0398 


.0796 


.0460 


.0858 


.0388 


.0419 


f 


9 


28.2743 


•0555 


•0354 


.0707 


.0409 


.0763 


-0344 


.0372 


tV 


lO 


31-4159 


.0500 


.0318 


.0637 


.0368 


.0687 


.0310 


•0335 


S^ 


i6 


50-2655 


.0312 


.0199 


.0398 


.0230 


.0429 


.0194 


.0209 


^v 


20 


62.8318 


.0250 


•0159 


.0318 


.0184 


.0343 


•0155 


.0167 



To obtain the size of any part of a circular pitch not given in the 
table, multiply the corresponding part of i'' pitch by the pitch re- 
quired. 



pitch line is 1.1571 -^ 21 = .0551 and the whole depth is 2.1571 -^ 
21 = .1027 inches. These could also have been obtained by split- 
ting the difference between the figures for 20 and 22 pitch. The 
same can be done for circular pitch except that we multiply instead 
of divide. 



I02 



GEARING 



DIAGRAM FOR CAST-GEAR TEETH 

The accompanying diagram (Fig. 2) for laying out teeth for cast 
gears will be found useful by the machinist, patternmaker and drafts- 
man. The diagram for circular pitch gears is similar to the one 
given by Professor Willis, while the one for diametral pitch was 
obtained by using the relation of diametral to circular pitch. 



Circular 




LLlL 



V 2" 

J. I , I, I , I I I, 1, 1 , 1 , 1 , 1, J , I, 



, 1,1 . 1 , 1,1 , 1,1 ,1 , 1 




Figs. 2 and 



By the diagram the relative size of a tooth may be easily deter- 
mined. For example, if we contemplate using a gear of 2 diametral 
pitch, by referring to line H K, which shows the comparative distance 
between centers of teeth, on the pitch line, it will be observed that 



LAYING OUT SPUR GEAR BLANKS 103 

2 diametral pitch is but little greater than i^ inches circular pitch, 
or exactly 1.57 inches circular pitch. This result is obtained by 
dividing 3.1416 by the diametral pitch (3.1416 divided by 2 equals 
1.57). In similar manner, if the circular pitch is known, the diame- 
tral pitch which corresponds to it is found by dividing 3. 141 6 by the 
circular pitch; for example, the diametral pitch which corresponds 
to 3 inches circular pitch is by the line H K a. little greater than i 
diametral pitch, or exactly 1.047 (3.i4i6"divided by 3 equals 1.047). 
. The proportions of a tooth may be determined for either diametral 
or circular pitch by using the corresponding diagram. 

Continue, for illustration, the 2 diametral pitch. We have found, 
above, the distance betvv^een centers of teeth on the pitch line to be 
a little more than ih inches (1.57 inches). The hight of tooth above 
pitch line B' C will be found on the horizontal line corresponding 
to 2 pitch. The distance between the lines A' B' and A' C on this 
line may be taken in the dividers and transferred to the scale below. 
Thus we find the hight of the tooth to be \% inch. In the same 
manner the thickness of tooth B' D', width of space B' E', working 
depth B' F' and whole depth of tooth B' G' may be determined. 

The backlash or space between the idle surfaces of the teeth of 
two gear wheels when in mesh is given by the distance D' E'. The 
clearance or distance between the point of one tooth and the bottom 
of space into which it meshes is given by the distance F' G' . The 
backlash and clearance will vary according to the class of work for 
which the gears are to be used and the accuracy of the molded pro- 
duct. For machine molded gears which are to run in enclosed cases, 
or where they may be kept well oiled and free from dirt, the backlash 
and clearance may be reduced to a very small amount, while for 
gears running where dirt is likely to get into the teeth, or where 
irregularities due to molding, uneven shrinkage, and like causes, enter 
into the construction, there must be a greater allowance. The 
diagram is laid out for the latter case. Those who have more favor- 
able conditions for which to design gears should vary the diagram 
to suit their conditions. This can be done by increasing B D and 
decreasing B E, and by increasing B C or decreasing B G, or both, 
to get the clearance that will best meet the required conditions. The 
same kind of diagram could be laid out for cut gears, but as tables 
are usually at hand which give the dimensions of the parts of such 
gears, figured to thousandths of an inch, it would be as well to consult 
one of these. 

LAYING OUT SPUR GEAR BLANKS 

Decide upon the size wanted, remembering that 12-pitch teeth 
are j\ deep and 8-pitch — as in the drawing — | deep, etc. Should 
it be 8 pitch, as shown in the cut, draw a circle measuring as many 
eighths of an inch in diameter as there are to be teeth in the gear. 
This circle is called the Pitch Line. Then with a -radius J of an inch 
larger, draw another circle from the same center, which will give 
the outside diameter of the gear, or f larger than the pitch circle. 
Thus we have for the diameter of an 8-pitch gear of 24 teeth, -2/-. 
Should there be 16 teeth, as in the small spur gear in the cut, th? 



I04 



GEARING 



outside diameter would be V? the number of teeth being always 
two less than there are eighths — ivhen it is 8 pitch — in the outside 
diameter. 

The distance from the pitch line to the bottom of the teeth is the 
same as to the top; excepting the clearance, which varies from \ of 
the pitch to y^ of the thickness of the tooth at the pitch line. This 
latter is used by Brown & Sharpe and many others, but the clearance, 
being provided for in the cutters the two gears would be laid out to 
mesh together just f . 

These rules apply to all pitches, so that the outside diameter of 
a 5-pitch gear with 24 teeth would be 3-; if a 3-pitch gear with 40 
teeth it would be V'. Again, if a blank be 4I (%^) in diameter, and 
cut 6 pitch, it should contain 23 teeth. 




y^'UiQ^^ 8 Pitch - 24 Teeth 
35i" Outside Diam. 




Fig. 4. — Laying out a Pair of Gears 



Actual Size of Diametral Pitches 

It is not always easy to judge or imagine just how large a given 
pitch is when measured by the diametral system. To make it easy 
to see just what any pitch looks like the actual sizes of twelve di- 
ametral pitches are given on the following page, ranging from 20 
to 4 teeth per inch of diameter on the pitch line, so that a good idea 
of the size of any of these teeth can be had at a glance. 



ACTUAL SIZES OF GEAR TEETH 105 



/\fvr\ (Myp^ |/w^ 



20 p. 



18 P. 



16 P. 



^rvAA^ /vv^ f^^^ 



14 P.. 



12 P. 




9 P. 





7 F. 



6 P. 





5 P, 



4^. 



io6 



GEARING 



LAYING OUT SINGLE CURVE TOOTH 

A VERY simple method of laying out a standard tooth is shown 
in Fig. 5, and is known as the single curve method. Having calcu- 
lated the various proportions of the tooth by rules already given, 
draw the pitch, outside, working depth and clearance or whole depth 
circles as shown. With a radius one half the pitch radius draw the 
semicircle from the center to the pitch circle. Take one quarter 
the pitch radius and with one leg at top of pitch circle strike arc 
cutting the semicircle. This is the center for the first tooth curve 
and locates the base circle for all the tooth arcs. Lay off the tooth 
thickness and space distances around the pitch circle and draw the 
tooth curves through these points with the tooth curve radius already 
found. The fillets in the tooth corners may be taken as one seventh 
of the space between the tops of the teeth. 



Tooth Curve 'Rad^u^ 
One quarter of Pitch RadiUB 




Fig. 5. — Single Curve Tooth 



PRESSURE ANGLES 

We next come to pressure angles of gear teeth, which means the 
angle at which one tooth presses against the other and can best be 
shown by the pinion and rack. Figs. 6 and 7. 

The standard tooth has a 141 degree pressure angle, probably 
because it was so easy for the millwright to lay it out as he could 
obtain the angle without a protractor by using the method shown 
for laying out a thread tool (see Fig. 14). As the sides of an involute 
rack tooth are straight, and at the pressure angle from the perpen- 
dicular, draw the line of pressure at 14^ degrees from the pitch line. 
The base circle of the tooth arcs can be found by drawing a line 
from the center of the gear to the line of pressure and at right angles 
to it as shown, or by the first method, and working from this the tooth 



STUB-TOOTH GEARS 



107 



curve can be drawn by either the single-curve method or, as is more 
usual, by stopping the curv« from two or more points on this same 
circle. 

The difference between the 14^- and 20-degree pressure angles 
can be seen by comparing Figs. 6 and 7. Not only is the tooth 
shorter, but the base is broader. The base circle for the tooth arcs 
is found in the same way as before. 

This form of tooth is largely used in automobile transmission and 
similar work. William Sellers & Co. use a 20 degree pressure 
angle with a tooth of standard length. 



Vy* Clesfrance or Bottom I \ Base Circle for Toolh Arcs 

« V^ Working Pepth \ Pitch Circle — 

Y iA ^4^- — Outside Diameter | \ , 




Fig. 6. — Standard Tooth 



STUB-TOOTH GEARS 

Any tooth shorter than the regular standard length is called a 
"stub" tooth, but like the bastard thread there have been many 
kinds. In 1899 the Fellows Gear Shaper Company introduced a 
short tooth with a 20-degree pressure angle instead of the usual 14^- 
degree. This gives a broader flank to the tooth and makes a stronger 
gear, especially for small pinions where strength is needed. While 
the Fellows tooth is shorter than the standard tooth there is no fixed 
relation between them, as, on account of the tooth depth graduations 
of the gear shaper, it was thought best to give the new tooth depth 
in the same scale which is shown in the following table. This means 
that if the pitch is 4 it has the depth of a 5-pitch standard tooth 
divided as shown. The clearance is one-quarter the addendum or 
dedendum. 



io8 



GEARING 



Table of Tooth Dimensions of the Fellows Stub-Tooth Gear 



fl 


























Stub 
Tooth 


Has Depth 
of Standard 


Thickness 
on 


Addendum 


Dedendum and 
Clearance 


dt 


Pitch 


Tooth 


Pitch Line 




s 












^ 


4 


5 


.3925 


.200 


.250 


^ 


s 


7 


.314 


.1429 


•1785 • 


1 


6 


8 


.2617 


.125 


.1562 


1 


7 


9 


.2243 


• III 


.1389 


^ 


8 


lO 


.1962 


.100 


.125 


rV 


9 


II 


.1744 


.0909 


.1137 


H 


lO 


12 


•157 


.0S33 


.1042 


li 


12 


14 


.1308 


.0714 


.0893 




Fig. 7, — Stubbed Tooth 



The Nuttall Company also use a 20-degree stub tooth, but have ai 
fixed length or depth in the following proportions. 

Addendum = .25 X circular pitch instead of .3683. 

Dedendum = .30 X circular pitch instead of .3683. 

Working depth = .50 X circular pitch instead of .6366. 
Clearance >= .05 X circular pitch same as standard. 

Whole depth = .55 X circular pitch instead of .6866. 



SIZES OF GEAR BLANKS 



109 



Table for Turning and Cutting Gear Blanks 

FOR standard length TOOTH 



Pitch 


16 


1 12 


10 


8 


Pitch 


16 


1 12 


1 10 


1 8 


Depth 
of Tooth 


•135 


.180 


.216 


.270 


Depth 
of Tooth 


.135 


.180 


.216 


.270 


No. of 
Teeth 


Outside Diameter 


No. of 
Teeth 


Outside Diameter 


10 


3 

4 


I 


lA 


I* 


51 


3A 


4A 


5x% 


6f 


II 


if 


irV 


lA 


If 


52 


3l 


4A 


5x% 


6f 


12 


I 


lA 


lA 


If 


53 


3A 


•4A 


5A 


6| 


13 


if 


lA 


lA 


li 


54 


Sh 


4A 


5x% 




14 


I 


lA 


lA 


2 


55 


3A 


4A 


5A 


7i 


15 


ItV 


lA 


lA 


2i 


56 


^f. 


4x1 


5A 


7i 


16 


li 


it% 


lA 


2i 


57 


3H 


4x-2- 


5x% 


7I 


17 


ItV 


iiV 


lA 


2f 


58 


3f 


5 


6 


7I 


18 


li 


lA 


2 


2| 


59 


3if 


5A 


6A 


7f 


19 


lA 


lA 


2A 


2| 


60 


sl 


5A 


6A 


7f 


20 


If 


iM 


2A 


2f 


61 


3\% 


5A 


6A 


7I 


21 


ItV 


lii 


2A 


2i 


62 


4 


5x% 


6x^0 


8 


22 


li 


2 


2A 


3 


63 


4A 


5A 


6A 


8i 


23 


I^ 


2A- 


2A 


3l 


64 


4j 


5x^2 


6A 


8i 


24 


If 


2A 


2A 


3i 


65 


4A 


5A 


6A 


81 


25 


•lii 


2A 


2A 


3f 


66 


4i 


5x% 


6A 


8^ 


26 


If 


2A 


2A 


3i 


67 


f 


6A 


8f 


27 


lit 


2A 


2A 


3l 


68 


5it 


7 


8f 


28 


Ij 


2 A 


3 


3f 


69 


4A 


5ii 


7A 


H 


29 


iM 


2tV 


3A 


3i 


70 


4h 


6 


7A 


9 


30 


2 


2A 


3A 


4 


71 


4A 


6A 


ZaV 


9i 


31 


2tV 


2t% 


3A 


4i 


72 


4t 


6x\ 


7x% 


9i 


32 


2i 


2M 


3A 


4i 


73 


4H 


6A 


7A 


9l 


33 


2A 


2^ 


3A 


4f 


74 


4f 




7* 


9\ 


34 


2i 


3 


3A 


4i 


75 


4i| 


6A 


7xV 


9l 


35 


2tV 


3A 


3A 


4f 


76 


4i 


6x'i 
6x^3 


7A 


9f 


36 


2f 


3A 


3A 


4f 


77 


4H 


7A 


9I 


2>1 


2tV 


i 


3A 


4| 


78 


5 


6A 


8 


10 


38 


2i 


4 


5 


79 


5A 


6A 


8A 


loi 


39 


2A 




4A 


5l 


80 


5J 




8A 


loi 


40 


.2| 


4A 


5i 


81 


5A 


6H 


^xV 


lof 


41 


2H 


3A 


4A 


5i 


82 


s\ 


7 


8A 


loj 


42 


2| 


3A 


4A 


5^ 


83 


5A 


7A 


8A 


lof 


43 


2II 


3A 


4A 


5f 


84 


5I 


7A 


8A 


lof 


44 


2| 




4A 


5f 


85 


5A 


7A 


8A 


loi 


45 


2H 


3tI 


4tV 


sl 


86 


5i 


7A 


8A 


II 


46 


3 


4 


4A 


6 


87 


5A 


7A 


8A 


Hi 


47 


3tV 


4A 


4A 


6i 


88 


^K 


7V 


9, 


II4 


48 


3i 


4A 


5 


6i 


89 


5H 


7xV 


9A 


Ilf 
II2 


49 


3tV 


4A 


5A 


6| 


90 


5f 


7A 


9A 


50 


3i 


4x^2 


5A 


6i 


91 


5if 


7A 


9x'o 


Ilf 



no 



GEARING 



Table for Turning and Cutting Gear Blanks 

FOR standard length TOOTH 



Pitch 


16 


12 


10 


8 


Pitch 


16 


12 


10 


8 


Depth 
of Tooth 


•135 


.180 


.216 


.270 


Depth 
of Tooth 


•135 


.180 


.216 


.270 


No. of 
Teeth 


* Outside Diameter 


No. of 
Teeth 


Outside Diameter 


92 


5f, 


7^1 


9A 


llf 


^33 


8A 


11^ 


I3to 


i6| 


93 


sH 


7-h 


9t% 


ll| 


134 


^K 


IIT2 


i3to 


17 


94 


6 


8 


91? 


12 


135 


8t\ 


IlT^¥ 


i3tV 


i7i 


95 


6tV 


8t\ 


9t'o 


I2i- 


136 


8f 


iiti 


i3to 


174 


96 


6J 


8t\ 


9A 


I2J 


137 


8-* 


IIT2 


i3to 


17! 


97 


6t\ 


8A 


9tV 


I2| 


138 


8f 


IIT2 


14 


i7i 


98 


6i 


8t\ 


10 


I2| 


139 


8-1 


IIT2 


i4xV 


i7f 


99 


6t6 


8tV 


iotV 


I2| 


140 


8h 


lilt 


i4x'o 


17I 


100 


6| 


8A 


iot^ 


I2| 


141 


8i* 


Ilii 


1 4x7 


17I 


lOI 


6tV 


81^2 


iot% 


I2| 


142 


9, 


'^, 


14x^0 


18 


102 


6i 


8A 


iot% 


13 


143 


9tV 


I2tV 


i4x'o 


i8| 


103 


6t\ 


8t\ 


iot^o 


i3i 


144 


9i 


I2A 


14x7 


1 81 


104 


6| 


8it 


loA 


i3i 


145 


9t^. 


I2A 


i4xV 


i8| 


105 


6H 


8H 


iotV 


i3f 


146 


9i 


I2t% 


i4xV 


i8i 


106 


6; 


9 


lOxV 


i3i 


147 


9t6 


I2fV 


I4x% 


i8f 


107 


6-1 


9t\ 


lo/o 


i3t 


148 


9f 


I2A 


15 


i8| 


108 


61 


9t\ 


II 


13! 


149 


9t's 


I2tV 


i5tV 


i8| 


109 


6H 


9fV 


iitV 


13I 


150 


9i 


I2A 


i5t^o 


19 


no 




9t\ 


IIA 


14 


151 


9t\ 


I2A 


i5i% 


i9i 


III 


7tV 


9t\ 


IIT% 


i4i 


152 


9l 


I2II 


15/0 


i9i 


112 


7J 


9t\ 


IIT% 


ui 


153 


9H 


I2ii 


i5tV 


i9t 


113 


7tV 


9tV 


IlT% 


I4| 


154 


9- 


13 


i5to 


i9i 


114 


7i 


9t\ 


IlT^O 


142 


155 


9x1 


i3tV 


i5to 


i9f 


115 


7tV 


9t% 


iitV 


I4f 


156 


9I 


i3t2 


i5to 


19! 


116 


71 


9if 


IIT^^ 


I4f 


157 


9H 


i3t^2 


i5to 


19I 


117 


7tV 


9ii 


IIT% 


14I 


158 


10 


i3i\ 


16 


20 


118 


7J 


10 


12 


15 


159 


iotV 


i3t2 


i6xV 


20i 


119 


7f6 


iotV 


I2tV 


i5i 


160 


lol 


i3t% 


16x^0 


20i 


120 


7 ' 


IOt\ 


J2^ 


i5i 


161 


loA 


i3tV 


i6x% 


20| 


121 


7-i 


I0T2 


12^ 


i5i 


162 


loi 


i3tV 


i6t% 


20^ 


122 




I0T2 


I2t% 


15^ 


163 


I0T6 


i3t\ 


i6x^^ 


20f 


123 


7-1 


loj'a 


12^ 


15I 


164 


io| 


i3tI 


i6x% 


20f 


124 




iot% 


I2tV 


i5f 


165 


I0T6 


13H 


i6xV 


20J 


125 


7I1 


I0T2 


I2to 


i5i 


166 


loi 


14 


i6xV 


21 


126 


8 


iot\ 


I2tV 


16 


167 


I0T6 


14x1 


16x^0 


21J 


127 


8tV 


IOt'2 


12X^0 


i6i 


168 


lof 


i4x\ 


17 


2ii 


128 


8| 


loll 


13 


i6i 


169 


loH 


i4xV 


1 7 1^0 


2lf 


129 


8tV 


loH 


i3tV 


i6f 


170 


I of 


I4t2 


i7t% 


21^ 


130 


81 


II 


i3t% 


i6i 


171 


iotI 


14A 


1717 


2I| 


131 


8tV 


iitV 


i3t% 


1 61 


172 


io| 


14A 


i7to 


2lf 


132 


8f 


IIT^^ 


^3t\ 


i6f 


173 


loH 


I4tV 


i7t7 


2l| 



PITCH DIAMETERS OF GEARS 



III 






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112 



GEARING 



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^ ::::::::::::::::::;::::::::::: : 



PITCH DIAMETERS OF GEARS 



113 



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444iou^'toiniAioioioi/^ir>toioio vovd oovdvdvdvd^doo^d-o^vd i^i>- 


00 
M d 


too ^0^0 fO^ c/50 "OVO "OVO c^O fOvO O r^O O r0>0 O N^\a O 
c^oioroMOoor-i^cowOooOintOHOoor-xocoMOoovoio ro m x'F. ih 

ir;^ t^oo qoq>-;M^^"7 "jp^ t--oo qoOMMr^'+io liovq t^co a « m 
lA lA in vo lovd oMSvd^JOOvd^vdvdo t^i>.rii<.t>.r^t^t^t4t4t^ riod oc 00 06 


2I 


t^co q H M ^ ^ 190 t-.co q q H M CO ■* lovq t^oo q q >-; <^ ^ -+ v~,\o r-oo o> 
vdo^ t-lr^t^t^(>.t^r^t^t>. t^od cdcdodooooodododod d>d^ dv_d> c< dv d' d> dv d^ 


CO d 


ir, 0»nOioOi>^OiJig>nOioqioO'00>r>0>J^OioO>nOioOioO>/^Oi/1 
r^OMinr^OMiot-OMior^OMu^t^OMiot^OMiot^OMiof-OMior-. 
cc 100 r-OO w M <^ if^.O t-.CO q M M -0 vr,0 t-~CC q w m ro VOO t^oO O h M ro 

ooodooocoodd^dd-ddddddddddddMHHMHwwwoioJMM 


-o d 


vO rOOvO fOOO rOOO ^OOO roOVD fOOO fOOvO r^OvO <r>00 rCO<5 -OO 
vO fOOO ro 00 rOOO roOO rOOO fOOvO roOO rOOO fOOO fOOO r^O 

M <v-, upvq 00 q M CO upvq <» q h to too co q m co »o^5 co q « co iovo 00 « -^ Co 

H w H w M M M M M M oj COCOCOcOCOCO-:t-44444>OlO>OlOl/^ l>-,VO O vO MS 


lod 


^^cg 8 S ^v§^ 8 S ^^^ 8 S ^^<g 8 S ^^^ 8 S ^^^ 8 8 ^S^ 

coco'o4't444wioio>o >o\d vdvdvdvd r^t>.t^t^ r-^od ododoooo' d d 6^ d d 


00 
^d 


;c8^9,ic8^s>ic8J?ajc8J?a:c8^s>ie8^aie8i?as8i?aie 
^ tr ^ ^ ^ ^ ^ ^ ^ ^ ? 2^ ? s S S 8 ^ j:i ^ ^ 5^ ^ ?i ^ ^ 5? ?? J? jf ^ ^ d" 




C0~0 COO <00 COVO cOMD COO COO O COO O coO O coO O COO O 

COO COO COO COO g COO COO COO 5 fooo coo coo 5 coo 

coo coo covD coo O coO O coO O coO O COO O cOO O coO Q coO 

M M c5coco444ioio lAo vd o f-^ f^ r^oo oocdddddddMMMMrJMco 

NMMMMMMMMMMMMMMMMMMMMMMCOCOCOCOtOcOCOCOCOCO 




eg Sv8 8 ^.g 8v8 8 ^<g Svg 8 ^<g 8^ 8 ^<g S^g 8 ^<g S.8 8 |c§ 8vg 

o t^ 1-^00 ododdvdvddoMiHMMMcofO'^'i-'*!') »oo o o t~- t-^oo od od dv di 

M M M M M M M M tOfOfO<OfOtOco^OcOcOtOcO^OcOtOcocOcOc0^0cO^OcocOfO 




S>89>82,8a8a8a8S>8S>89>8 9-.82,8a8a8S>8a8a8a 

CO ■* "* >o loO O r^ r^c« cdodiddi-i>-iMcicoco-^-T>o vovo O r-^ t-^od od o d> 
ro«:i'OCOcOco^"^'OCOCOcOcOrJ--*rtTi--,j-^Tj-Tl--C'3-Ttrt'^'t-*^'*-*'<j-'<l-' 


.! 


o cogo cogo cogo cooojooo cooo cooo cooo cooo cooo coo 
o cooo cooo cooo coootooo cooo cooo cooo cooo cogo coo 

tj- lovd vd t^od oddvddwMMfo^'ct u-o o t-^cd odd>doMM'Mco-*-4- »A,o 

■^t'*r)-T)-^^-T>0>ouii/->ioioio>oioiou-)ioioio iTiO OOOOOOOOO 


QCJ 


^ ::::::::::::::: i : M :: i ;: i : M :::: i 



114 



GEARING 





u-;iiiuiiOii^»jSioio«0'Oioin\oir)ioioi/>iOio ICO vd\Osd^\d<)>Ovd 




ly^M t^foOvO <NO0 lOM t^?oQO (NC«inH tCJoOO c?<» 10 w IC Jo 8 
<N ro fO ■* >o "^vO t-e» oOOvOOwMNrOro-^l-i/i lovo vO r-OO 00 0> O 
vdo^vd>0^o'vdvdv6vd^ t^r^r^t^t^r^i^Ltit^t^t^tir^t^t^ t^oo 


J 
?d 


N T}-»/>t^00 M N TfV5t^00 M M 'tiJit^oo Own rf m t^oo O h N 

TtMCO ION Ot^-*WCOlON Ot^-<tMOO»ON OJ^-*MOOVON Ot^"* 

M N N ro -^ »o vovO i~~ r^oo OiOOmnnco-^io lOO t^ f^OO 0> O O w 

t^t^r^t^j^t^i-^rCtC.t>r^ t^oo.oo 06 06 dod ooododododododoo 6d>6 


00 

2d 


ooooocjododoooooo 6'6'0><><^0'0'0'<^<>0'<^0 6 6 6 6 6 6 6 6 


2I 


O M N fo rj- \n\o t~.00 O O w N <<5 <t lovo t^OO Oi O H N fO •* tOO r-00 


00? 


0>o0io0io0»o0>o0to0»o0>oov>0>o0>o0to0io0^0 
ONiot>-ON»or^ON»or^ONinr^ONint^ONu-ir^ONiot^O 
»Ovo r-oq O M N ro to\q r~-00 O M N CO lo^ t-.00 O m n ro lovo t^oO O 
N N N N co^orO^0fOrC^^fr>4't444444l^^O>O>J^lO^OlO ir>\6 


vo 6 


vO lOQvO r^OO toOO f^OO tOQO rOOO <nOO fOOO tOOvO fO 
VO rOOO roOO foOO rOOO "^OO roOO fOO'O pOOO rOOO rO 

ooo q M coi>)vqoo q w ovoooo q m tolovqoo O -- toinooo O M CO 
vo vo ri t^ !>. ti t^ t^od ododododoo d>6vc>6v6>dd d d d d d « m w 


00 

lod 


8 g ^^^ 8 S ^^cg 8 S ^^cg 8 S ^^cg 8 8 ^^cg 8 S ^S 

dddddMMWM>-.NNNNNrocorOfOff>4't4-*-*»oir)>oio 

NNNNNNNNNNNNNNNNNNNNNNNNNNNNN 


10 

00 

■*d 


0>oOinOtoO>oQ»no<oO»oO»oO>oO>oO»oOioOioOioO 

ONlOt^ONlOt-ONlOt^ONlOt^ONlOt^ONinr-ONlOt^O 


ic lo lo lio^d vd vd \d t^ t^ i^ i^od odododdvddvdvdd ddMMMMN 

NNNNNNNNNNNNNNNNNNNNfOfOCOfOCOCO^OeOrO 




COO O fOO O f<^vO O rovO O r0>0 O fO<0 O COVO O ^0^O O f^vO O fC>0 
POO O POO O OO O fOO O fOO O fOO o ^oo o coo O coo O coo 

coo q coo q coo q coo q coo o coo o coo o coo o coo o coo 
CO CO 4 4 4 -o >A uio o o t^ t^ r^od ododdvdvd<ddd wwmnnn 

rOcococococococococococococOcococOcocOcOTl-^Tl-Tt-^Tl-Tt'^'t 


ION 

pj M 


8 ^cg S^ 8 ^cg S^ 8 ^^ 85 8 %& 85 8 ^^ 85 8 ^cg 8 

OOOMMNNN^^^^^^^OOO^^odcdodddddOM 


M H 


8a89,8S,89,8a8a8a8S>89>8a8S>8a8a8a8 

ddwi-'NN'oco^'tiA loo o 1^ t>-od odd>d>ddw>-<csp)coco4 
iotOLoLoioioioioiovo>oir>>oioio>oioioi>) iho O O O O loo O O 


-1 
M C4 


O COOO COOO COOO coOO COOO COOO coOO COOO COOO CO 




H :::::::::::::::::::::::::::: : 


iSssssslsssSHHSSH^H'SSsHHsJssEs 



GEAR CUTTERS AND CUTTING 



IIS 



B. & S. INVOLUTE GEAR TOOTH CUTTERS 



No. I will cut wheels from : 
No. 1 1 will cut wheels from 
No. 2 will cut wheels from 
No. 27 will cut wheels from 
No. 3 will cut wheels from 
No. 3i will cut wheels from 
No. 4 will cut wheels from 
No. 45 will cut wheels from 
No. 5 will cut wheels from 
No. Si will cut wheels from 
No. 6 will cut wheels from 
No. 65 will cut wheels from 
No. 7 will cut wheels from 
No. 7i will cut wheels from 
No. 8 will cut wheels from 



35 teeth to a rack. 
80 teeth to 134 teeth. 
55 teeth to 134 teeth. 



42 teeth to 
35 teeth to 
30 teeth to 
26 teeth to 
23 teeth to 
21 teeth to 
19 teeth to 
17 teeth to 
15 teeth to 
14 teeth to 
13 teeth to 
12 teeth to 



54 teeth. 
54 teeth. 
34 teeth. 
34 teeth. 
25 teeth. 
25 teeth. 
20 teeth. 
20 teeth. 
16 teeth. 
16 teeth. 
14 teeth. 
13 teeth. 



The eight cutters represented by the whole numbers constitute the 
regular set of cutters generally used for each pitch of tooth. The 
half numbers increase the set to 15 and gives teeth which are theoret- 
ically more correct. In some work special cutters are used for each 
gear but the 15 cutters in a set offer all that most cases require. 

Table Showing Depth of Space and Thickness of Tooth 
IN Spur Wheels, when cut with these Cutters 



Pitch 


Depth to be 


Thickness of 


Pitch 


Depth to be 


Thickness of 


of 


cut in Gear 


Tooth at Pitch 


of 


cut in Gear 


Tooth at Pitch 


Cutter 


Inches 


Line. Inches 


Cutter 


Inches 


Line. Inches 


li 


1.726 


1^257 


II 


.196 


•143 


i^ 


1.438 


1.047 


12 


.180 


• 131 


If 


1.233 


.898 


14 


• 154 


.112 


2 


1.078 


.785 


16 


• 13s 


.098 


2- 


.958 


.697 


18 


.120 


.087 


2- 


.863 


.628 


20 


.108 


.079 


2? 


.784 


.570 


22 


.098 


.071 


3 


.719' 


•523 


24 


.090 


.065 


3h 


.616 


•448 


26 


.083 


.060 


4 


•539 


•393 


28 


.077 


.056 


5 


.431 


.314 


30 


.072 


.052 


6 


•359 


.262 


32 


.067 


.049 


7 


• 308 


.224 


36 


.060 


•044 


8 


.270 


.196 


40 


.054 


.039 


9 


.240 


•175 


48 


•045 


•033 


10 


.216 


.157 









BLOCK INDEXING IN CUTTING GEAR TEETH 

Block or intermittent indexing is a method to increase the output 
of gear cutters by allowing the feed and cutting speed to be increased 
without unduly heating the work. This is done by jumping from 
the tooth just cut to a tooth far enough away to escape the local 
heating and on the following rounds to cut the intermediate teeth. 
While the indexing takes a trifle more time, the heat is distributed so 
that faster cutting can be done without heating and dulHng the cutter. 

The following table gives the indexing of gears from 25 to 200 
teeth and is worked out for the Brown & Sharpe gear cutter but can 
be modified to suit other machines. 



ii6 



GEARING 



DsiQ SatiiooT JO sumx 


NNNNMN<NN(NNNNNIN«WNMMNO)N(Sf)NN ,1 


i3Monoj pnoD3s 1%^^^^"^^^^%?-^ 9,^^z^^ S;^^^=5^^;g ^ 


aaAUQ pncoas [ ^ o? go? g 8^cg go?^ g RS g S.^°^ gcg <;? goj g Re? 


a9Mono J isiij 1 R ^ ^ g,^ S!. g, ^^ ^ S,5 -S ^5 g.vg ?v8 v8 ^S 5,S S^S 


J3AUQ }SJl j^ 


22§2§^2°2§2 22^22222222222^ 


30UQ XB paxapUJ 'O^ | u^ l> >o i> ^O t^irim t^oo >i^ r^ 0> »o<o r~ioiovoJ--iot^ior~l^ || 


in3 aq o; q^aa^ 


>O<5OOvCOr^t-r^i>r^t^000000000000C000 0>OvO>0>OvO 


DSJQ 3ui:5[DOq^ JO SUJTIJL |f)<NMNCINM<S(NN(NNNNMMMNNNeiN<N<NlNNN 


jaMonoj pnoDas |:2 ^ S, ^^g ^ ^^v^ 5;§ ^ R ^ J?> R^ ^ S S>^5 S ^ '^.J 


ja.vuQ paoaas o? go? S, go^c^cg ^ g^ gc§ gcg ~g g Reg g^ g<g R R go? 


jaMonoj isjij 1 a o o o o o o go o o o o « o 50 2 « g ^o 00 


javUQ JSJTJ 


2222§22222222°§S.88888888888 


aaUQ 1^ paxapuj -O^ |t-iot^io>ot-t-io^«Jit^>oioro ^J^^O >/^0 u^ u^ r^ lo u~, VO.O 10 r-| 1 


;n3 aq 01 qpax 


CO'^IOOOO OO N c^TMovOOO O w ro-^i^t^oo O M fO tT »ovo 




asiQ Sni-5tao'j[ jo snjnx I<n(n(s<n<n<n<nnmn(nnoi(m(nn(n(nn<nmnnnp)nn 


jaMonoj pnoaas \^%^ ^^^^ §;^^^ ? ^S 2>5 5 ? ^^^^'S^'Rg ^ ? 


aaAUQ puoaas | go? g R R g^ g^ g g^ ^S gS R^cg g.J?^ g^ R R^ 


aaMonojjsiH|oooooooooooooooooo;tooooooov^ 


aaAUQ jsjTj 


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aauQ ^B paxapuj "O^ |u^i-iot^ro>ot~.ir;-<tioio2 i^"^iott>t->A>»/^ t-00 >^oo c^ f- ttI 


jn3 aq o; q;aax 


O r~oO O M P) fO ■Tf i/ivO 00 0> O <M t ''lOO O m N ■^ >o\0 r~ Cv O w 
000000O>OvO>aOvOvOvO>O>OOOOO>-iwi-iMMMMMNN 


aSIQ SUI-JIDOI JO SUjnX |w<NNN(N(NNN<NNN<NNaM<N<NtN<NP»««Pt(NN(NN 


aaMO„o J pnoaas | ^ 5 ?^^^ ^^ ^^ J?, ^^S ^ R R R S.^ ?^^ J?,^ o?§ 


aaAUQ puoaas | g g^ g^ go? gcg g^cg g gcg g g go? g^ g g^ g g^ 


jaAVonoj;s.H|o 00 0000 000 0500^0 00 00000 00 


jaAUQ ISJIJ 


888888888888888888888888888 




aaUO J^ paxapUI •OJsl|i/-,.y^TM/l^^r-.r>./^,./^^.^uiv,.oro.o.r>l-.r,^,oror-.o.ort 


■^nj aq o; qjaax |ii^ir)ioioi/-, u-;0-ovoovovovo>o<5 t-r-t-r-t-r- t-oo oo oo oo oo 


asiQ SnT-5[aoq; jo suanx l^^'^'^'tiN Tj-^TrTrfr'^-*^^-*T}-Ti-^-*'*Tj-n-^Tr<s 


jaAvono J puoaas | ^ ^ ^^'^S ^ ^ ?g ^ ^ R^^cg cS o?g §8 ?> S. S^^g ^S 


jaAuapnoaas | R g^ g gv8 g g^ g^.g g g g g g g g gR g g g go?^ 


jaMonojJsai^ aaaaaaaS>g>S>S>°^?=a?=a3.^3>^a3.?>?>?.aa 


jaAUQ ISJIJ 


888888888888888888888888888 


M M M M M M 


aaUQ IB paxapuj 'O^ \ rt n ^ flton rofOTtrO'<t>^>^>^>>^fOiouiu-)>ilt^i/^iA>o»ot^'*| 


mo aq oj tpaax 


|{?^?r^^g>sif^??S}?^J:?^^^^^??^^$<^5S>c,|i 



DIMENSIONS OF GEARS BY METRIC PITCH n? 



THE DIMENSIONS OF GEARS BY METRIC PITCH 

Module is the pitch diameter in mm. divided by the number of 
teeth in the gear. 

Pitch diameter in mm. is the Module muhipHed by the number 
of teeth in the gear. 

M = Module. 

D' == The pitch diameter of gear. 

D = The whole diameter of gear. 

N = The number of teeth in gear. 

D" = The working depth of teeth. 

t = Thickness of teeth on pitch line. 

/ = Amount added to depth for clearance; 
Then 

M = — or r— - — , 
N N + 2 
D' = N M. 

D = {N + 2) M. ^\ \>- 

^T D' D 

D" = 2 M. 
t = M 1.5708. 
M 1.5708 




/ = 



= .157 ^' 



The Module is equal to the part marked "S" in cut, measured 
in mm. and parts of mm. 
.Example: Module = 3.50 mm. 100 teeth. 
Pitch diameter = 3.5 X 100 = 350 mm. 
Whole diameter = (100 + 2) X 3-5 = 357 mm. 

Pitches Commonly Used — Module in Millimeters 





Corresponding 




Corresponding 


Module 


English 


Module 


English 




Diametral Pitch 




Diametral Pitch 


\ mm. 


50.800 


4.5 mm. 


5-644 


1 


33-867 


5 


5.080 


I 


25.400 


5-5 


4.618 


1.25 


20.320 


6 


4.233 


1-5 


16.933 


7 


3.628 


1-75 


14-514 


8 


3-175 


2 


12.700 


9 


2.822 


2.25 


11.288 


10 


2.540 


2-5 


10.160 


II 


2.309 


2.75 


9.236 


12 


2.117 


3 


8.466 


14 


1.814 


3.5 


7-257 


16 


1-587 


4 


6.350 







ii8 



GEARING 



SPROCKET WHEELS FOR BLOCK CENTER CHAINS 

N = No. of Teeth. E = ^' 

C = Diameter of Round Part of 
Chain Block. Tan D = 
Sin. E 



B 



+ Cos. E 



B 



Center to Center of holes in Chain 
Block. 
A = Center to Center of holes in side 

links. Pitch Diam. = — — — . 
Sin.Z) 

Outside Diam. = Pitch Diam. + C. 

Bottom Diam. = Pitch Diam. — C. 

In calculating the diameter of 

•Sprocket Wheels the Bottom Diameter is the most important. 

Diameter of Sprocket Wheels - 
A = .6*. B = .4" 




Fig. 9 



FOR 

c - 



BLOCK CHAINS V 



PITCH 



No. of Teeth 


Pitch Diameter 
Inches 


Outside Diameter 
Inches 


Bottom Diameter 
Inches 


6 


1-935 


2.260 


1. 610 


7 


2.250 


2.575 


1.925 


8 


2.566 


2.891 


2.241 


9 


2.882 


3.207 


2-557 


10 


3.198 


3.523 


2.873 


II 


3.515 


3.840 


3.190 


12 


3-832 


4.157 


3.507 


13 


4.149 


4.474 


3.824 


14 


4.466 


4.791 


4.141 


15 


4.784 


5.109 


4.459 


16 


5.102 


5.427 


4-777 


17 


5.420 


5.745 


5-095 


18 


5-738 


6.063 


5-413 


19 


6.056 


6.381 


5.731 


20 


6-374 


6.699 


6.049 


21 


6.692 


7.017 


6.367 


22 


7.010 


7-335 


6.685 


23 


7.328 


7-653 


7.003 


24 


7.646 


7.971 


7.321 


25 


7.964 


■ 8.289 


7.639 


26 


8.282 


8.607 


7.957 


27 


8.600 


8.925 


8.275 


28 


8.918 


9-243 


8-593 


29 


9-237 


9.562 


8.912 


30 


9-556 


9.881 


9.231 



DIAMETERS OF SPROCKET WHEELS 



119 



Calculating Diameters of 
Sprocket Wheels for Roller Chains 

N = Number of Teeth in Sprocket 
P = Pitch of Chain 
D = Diameter of Roller 

. -360^ 
^ ~ iV 

p 
Pitch Diameter = —. — t—- 
Sm. i A 

Outside Diameter = Pitch Diameter + D 
Bottom Diameter = Pitch Diameter — D 

Fig. 10 




Diameter of Sprocket Wheels for Roller Chains 1" pitch where 
D = .45. 

Diameter of Sprocket Wheels for Roller Chains of i'^ Pitch 
WHEN D = .45" 



No. of Teeth 


Pitch Diameter 


Outside Diameter 


Bottom Diameter 


in Inches 


in Inches 


in Inches 


6 


2- 


2-45 


1-55 


7 


2.305 


2-755 


1.85s 


8 


2.613 


3-063 


2.163 


9 


2.923 


3-373 


2-473 


10 


3-236 


3.686 


2.786 


II 


3-549 


3-999 


3-099 


12 


3.863 


4-313 


3-413 


13 


4.179. 


4.629 


3-729 


14 


4.494 


4-944 


4.044 


IS 


4.809 


5-259 


4-359 


16 


5.125 


5-575 


4-675 


17 


5-442 


5.892 


4-992 


18 


5.758 


6.208 


5-308 


19 


6.122 


6.572 


5.672 


20 


6.392 


6.842 


5-942 


21 


6.747 


7.197 


6.297 


22 


7.025 


7-475 


6.57s 


23 


7-344 


7-794 


6.894 


24 


7.661 


8. Ill 


7.211 


25 


7-979 


8.429 


7.529 


26 


8.296 


8.746 


7.846 


27 


8.614 


9.064 


8.164 


28 


8.932 


9.382 


8.482 


29 


9.249 


9-699 


8.799 


30 


9-566 


10.016 


9. 116 



I20 



GEARING 



A TABLE FOR DIMENSIONS FOR MITER GEARS 

_ The ^ accompanying table is of service in determining the prin- 
cipal dimensions of miter gears (center angle 45 degrees), the num- 
ber of teeth and the pitch being known. The table covers most of 
the possible number of teeth from 12 to 60, inclusive, and pitches 
from 2 to 10, inclusive, omitting 9. Values for face and cut angles 
correspond with designations in Fig. 11. 











't O O^ <> O 00 ■*^0>'''N vo^ tb lo '^ cs o><D^rO C^ ^ O lo 0> ^00 " o'h <N coo <N 00 ^ o 

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BEVEL GEARS 



121 




Fig. II, — Bevel Gear Parts 



BEVEL GEARS 

Bevel Gears are used to transmit power when shafts are not par- 
allel. They can be made for any angle, but are more often at right 
angles than any other. Right angle bevel gears are often called miter 
gears. The teeth are or should be radial so that they are longer at the 
outer end. The names of parts are sho\ATi in Fig. ii. These should 
be noted carefully, particularly the face angles. The earlier editions 
measured /oce angle at right angles to the axis, but this is now changed 
as shown. 

LAYING OUT BEVEL GEAR BLANKS 

In laying out bevel gears, first decide upon the pitch, and draw 
the center lines B B and C C, intersecting at right angles at A as shown 
in Fig. 12. Then draw the lines D D to E E the same distance each 




Fig. 12. — Laying out Bevel Geaib 



122 



GEARING 



side oi B B and parallel to it; the distance from D D to E E being 
as many eighths of an inch — if it be 8 pitch — as there are to be 
teeth in the gear. In the example the number of teeth is 24; there- 
fore the distance from D D to E E will be \*-, or i| inches each side 
oi B B. K K and L L are similarly drawn, but there being only 
16 teeth in the small gear, the distance from K K to L L will be -^/, 
or I inch each side of C C. Then through the intersections oi D D 
and L L, E E and L L, and E E and K K, draw the diagonals F A. 
These are the pitch lines. Through the same point draw lines as 
G G at right angles to the pitch lines, forming the backs of the teeth. 
On these lines lay off | of an inch each side of the pitch lines, and 
draw M A and N A, forming the faces and bottoms of the teeth. 
The lines H H are drawn parallel to G G, the distance between them 
being the width of the face. 

The face of the larger gear should be turned to the lines M A , and 
the small gear to iV ^ . For other pitches the same rules apply. If 
4 pitch, use 4ths instead of 8ths; if 3 pitch, 3ds, and so on. 

Bevel gears should always be turned to the exact diameters and 
angles of the drawings and the teeth cut at the correct angle. 




NG'No. of Teeth in Gear 
NP=No. of Teeth in Pinion 
CG = Center Angle of Gear 
CP= Center Angle of Pinion 



Fig. 13. — Finding the Cutter to Use 



Proportions of Miter and Bevel Gears 

To Find the Pitch or Center Angle: 

Divide the number of teeth in the gear by the number of teeth in 
the pinion. This gives the tangent of the pitch angle of the gear. 
Or divide the number of teeth in the pinion by the teeth in the gear 
and get the tangent of the pitch angle of the pinion. Subtracting 
either pitch angle from 90 gives the pitch angle of the other. 



CUTTERS FOR BEVEL GEARS 123 

To Find the Outside Diameter: 

Multiply the cosine of the pitch angle by twice the addendum 
and add the pitch diameter. 

To Find the Outside Cone Radius or Apex Distance: 

Multiply the secant of the pitch angle of the pinion by ^ the pitch 
diameter of the gear. 

To Find the Face and Cutting Angles: 

Divide the addendum by the outside cone radius or apex distance.. 
This gives the tangent of the addendum or outside angle. Subtract 
this angle from the pitch angle of the pinion to obtain the cutting 
angle of the pinion, and the face angle of the gear. Subtract the 
same addendum angle from the center angle of the gear to obtain 
the cutting angle of the gear and the face angle of the pinion. This 
gives a uniform clearance and is especially for use with rotary cutters. 

To Find Hight of Addendum at Small End of Tooth: 

Divide the addendum at the large end of the tooth by the outside 
cone radius. This gives the decrease in hight of the addendum for 
each inch of gear face. Multiply this by the length of the gear face 
and subtract the result from the addendum of the large end of the 
tooth. The difference is the hight of the addendum at the small 
end of the tooth. 



CUTTERS FOR BEVEL GEARS 

Lay out the bevel gears and draw lines A and B at right angles 
to the center angle line. Extend this to the center lines and meas- 
ure A and B. The distance A = the radius of a spur gear of the 
same pitch, and finding the number of teeth in such a gear we have 
the right cutter for the bevel gear in question. Calling the gears 
8 pitch and the distance A = 4 inches. Then 2 X 4 X 8 = 64 
teeth, so that a No. 2 cutter is the one to use. For the pinion, if B 
is 2 inches, then 2X2X8 = 32 or a No. 4 cutter is the one to 
use. 



124 GEARING 



USING THE BEVEL GEAR TABLE 

Take a pair of bevel gears 24 and 72 teeth, 8 diametral pitch. 
Divide the pinion by the gear — 24 -^ 72 = .3333. This is the tan- 
gent of the center angle of pinion. Look in the seven columns under 
center angles for the nearest number to this. The nearest is .3346 
in the center column, as all these are decimals to four places. Fol- 
low this out to the left and find 18 in the center angle column. As 
the .3346 is in the column marked .50 the center angle of the pinion 
is 18.50 degrees. Looking to the right under center angles for gears 
find 71 and add the .50 making the gear angle 71.50 degrees. Thus: 
Center angle of pinion 18.5 degrees. 
Center angle of gear 71.5 degrees. 

In the first column opposite 18 is 36. Divide this bj^ the number 
of teeth in the pinion, 24, and get 1.5 degrees. This is the angle 
increase for this pair of gears, and is the amount to be added to the 
center angle to get the face angle and to be deducted to get the cut 
angles. This gives 

Pinion center angle 18.5 + 1.5 = 20 degrees face angle. 

Pinion center angle 18.5 — 1.5 = 17 degrees cut angle. 

Gear center angle 71.5 -f 1.5 = 73 degrees face angle. 

Gear center angle 71.5 — 1.5 = 70 degrees cut angle. 

For the outside diameter go to the column of diameter increase 
and in line with 18 find 1.90. Divide this by the pitch, 8, and get 
.237, which is the diameter increase for the pinion. Follow the 
same line to the right and find .65 for the gear increase. Divide this 
by the pitch, .8, and get .081 for gear increase. This gives 

Pinion, 24 teeth, 8 pitch = 3 inches + .237 = 3.237 in. outside dia. 

Gear, 72 teeth, 8 pitch = 9 inches + .081 = 9.081 in. outside dia. 

To Select the Cutter 

Another way of selecting the cutter is to divide the number of 
teeth in the gear by the cosine of the center angle C and the answer 
is the number of teeth in a spur gear from which to select the cutter. 
For the pinion the process is the same except the number of teeth 
in the pinion is divided by the sine of the center angle. Formula 
NG NP 

Tangent of CG = ^ • Tangent of CP = -^ . 

NG 

Number of teeth to use in selecting cutter for gear = p; — ^rr; . 

Los CO 

NP 

Number of teeth to use in selecting cutter for pinion = -zr. — ^rp, • 

Sin CG 

Any pair of gears can be figured out in the same way, bearing in 
mind that when finding the center angle for the gear, to read the parts 
of a degree from the decimals at the bottom, and that for the pinion 
they are at the top. In the example worked out the tangent came 
in the center column so that it made no difference. If, however, 
the tangent had been .3476 we read the pinion angle at the top, 19.17 
degrees and the gear angle at the bottom, 70.83. By noting that 
the sum of the two angles is 90 degrees, we can be sure we are right. 



USING THE BEVEL GEAR TABLE 



125 



Bevel Gear Table 

SHAFT angles 90° 



;rj3 


i, >. _ 


<o u 














(U U 


L >» 


0^ 




< « 


Center Angle 


Hundredth Degrees 




^1 


^:2 1 


c >> 














S.^o 




^^^ 


^"« 


Left-hand Column read here 




•- 'S 


^^J 


«-sl 



















c If 


p5 







.17 


.33 


.50 


.67 


•83 


1.00 


■S'li 


I 


2.00 





.0000 


.0029 


.0058 


.0087 


.0116 


.0145 


•0175 


89 


•03 


2 


2 


00 


I 


•'3175 


.0204 


.0233 


.0262 


.0291 


.0320 


.0349 


88 


.07 


4 


2 


00 


2 


•0349 


.0378 


.0407 


•0437 


.0466 


.0495 


•0524 


87 


.10 


6 


2 


00 


3 


.0524 


•0553 


.0582 


.0612 


.0641 


.0670 


.0699 


86 


.14 


8 




99 


4 


.0699 


.0729 


.0758 


•0787 


.0816 


.0846 


.0875 


85 


•17 


10 




99 


5 


.0875 


.0904 


•0934 


.0963 


.0992 


.1022 


.1051 


84 


.21 


12 




99 


6 


.1051 


.1080 


.1110 


.1139 


.1169 


.1198 


.1228 


83 


.24 


14 




98 


7 


.1228 


.1257 


.127S 


.1317 


.1346 


.1376 


.1405 


82 


.28 


16 


J 


98 


8 


•1405 


•1435 


.1465 


.1495 


.1524 


.1554 


.1584 


81 


.31 


18 


I 


98 


9 


.1584 


.1614 


.1644 


.1673 


• 1703 


.1733 


.1763 


80 


•34 


20 




97 


10 


.1763 


•1793 


.1823 


.1853 


.1883 


.1914 


.1944 


79 




22 


I 


96 


II 


.1944 


.1974 


.2004 


.2035 


•2065 


•209s 


.2126 


78 


.41 


24 




96 


12 


.2x26 


.2156 


.2186 


.2217 


•2247 


,2278 


•2309 


77 


.45 


26 




95 


13 


.2309 


•2339 


.2370 


.2401 


.2432 


.2462 


•2493 


76 


.48 


28 




94 


14 


•2493 


.2524 


•2555 


.2586 


.2617 


.2648 


.2679 


75 


.51 


30 




93 


15 


.2679 


.2711 


.2742 


.2773 


.280^ 


.2836 


.2867 


74 


•55 


32 




92 


16 


.2867 


.2899 


.2931 


.2962 


.2994 


.3026 


•3057 


73 


•58 


34 




91 


17 


•3057 


.3089 


•3121 


•3153 


•318s 


•3217 


.3249 


72 


.62 


36 




90 


18 


•3249 


•3281 


-3314 


•3346 


.3378 


.3411 


•3443 


71 


.65 


37 




89 


19 


•3443 


•3476 


.3508 


•3541 


.3574 


•3607 


.3640 


70 


.68 


30 




88 


20 


.3640 


•3673 


.3706 


•3739 


.3772 


•3805 


.3839 




•71 


41 


I 


86 


21 


.3839 


.3872 


•3906 


•3939 


•3973 


.4006 


.4040 


68 


•75 


43 




85 


22 


.4040 


.4074 


.4108 


.4142 


.4176 


.4210 


•4245 


67 


.78 


45 




84 


23 


.4245 


•4279 


•4314 


.4348 


•4383 


.4417 


•4452 


66 


.81 


47 


^ 


82 


24 


•4452 


•4487 


•4522 


.4557 


•4592 


.4628 


.4663 


65 


.84 


49 


1 


81 


25 


.4663 


.4699 


•4734 


.4770 


.4806 


.4841 


.4877 


64 


.88 


50 


I 


79 


26 


.4877 


•4913 


•4950 


.4986 


.5022 


.5059 


•5095 


63 


.91 


52 


J 


78 


27 


•5095 


•5132 


.5169 


.5206 


•5243 


.5280 


•5317 


62 


•93 


54 


I 


76 


28 


•5317 


•5354 


•5392 


•5430 


•5467 


.5505 


•5543 


61 


•97 


56 




74 


29 


.5543 


.5581 


.5619 


.5658 


.5696 


•5735 


•5774 


60 


1. 00 


57 


^ 


73 


30 


.5774 


.5812 


.5851 


•5890 


•5930 


•5969 


.6009 


59 


1.03 


59 


I 


71 


31 


.6009 


.6048 


.6088 


.6128 


.6168 


.6208 


.6249 


58 


1.05 


61 




69 


32 


.6249 


.6289 


•6330 


.6371 


.6412 


•6453 


.6494 


57 


1.08 


63 




67 


33 


.6494 


•6536 


•6577 


.6619 


.6661 


.6703 


•6745 


56 


I. II 


64 




65 


34 


•6745 


.6787 


.6830 


•6873 


.6916 


.6959 


.7002 


55 


1. 14 


66 




63 


35 


.7002 


.7046 


.7089 


•7133 


.7177 


.7221 


.7265 


54 


1. 17 


68 




61 


36 


.7265 


•7310 


•7355 


.7400 


•7445 


•7490 


•7536 


53 


1.20 


69 




59 


37 


.7536 


.7581 


.7627 


•7673 


•7720 


.7766 


•7813 


52 


1.23 






57 


38 


.7813 


.7860 


•79='7 


•7954 


.8002 


.8050 


.8098 


51 


1. 25 






55 


39 


.8098 


.8146 


.8195 


•8243 


.8292 


•8342 


•8391 


50 


1.28 






53 


40 


•8391 


.8441 


.8491 


.8541 


.8591 


.8642 


.8693 


49 


1^31 






51 


41 


.8693 


.8744 


.8796 


.8847 


.8899 


.8952 


.9004 


48 


1-33 






48 


42 


.9004 


•9057 


.9110 


.9163 


.9217 


.9271 


•9325 


47 


1^36 


79 




46 


43 


•9325 


•9380 


•9435 


.9490 


•9545 


.9601 


•9657 


46 


i^39 


80 




43 


44 


.9657 


•9713 


.9770 


•9827 


.9884 


•9942 


1 .0000 


45 


1.41 


81 


1.41 


45 


1 .0000 


1.0058 


1.0117 


1.0176 


I.0235 


1.0295 


i^0355 


44 


1^43 










1.00 


.83 


.67 


•50 


-33 


.17 










Right Hand Column read here 



126 



GEARING 



SPIRAL GEARS 

The term spiral gear is usually applied to gears having angular 
teeth and which do not have their shafts or axis in parallel lines, 
and usually at right angles. Spiral gears take the place of bevel 
gears and give a smoother action as well as allowing greater speed 
ratios in a given space. When gears with angular or skew teeth 
run on parallel shafts they are usually called helical gears. 

The Calculation of Forty-Five Degree Spiral Gears 









No. of 




Thick- 








Pitch 




Pitch of 


Teeth 




ness of 






Circular 

Pitch 
(Normal) 


of 


Pitch 


Spiral in 


in Spur 


Outside 


Tooth at 


Depth of 


Clear- 


Cut- 


Diam. 


Inches to 


Same 


Diam. 


Pitch 


Tooth 


ance 


ter 




One Turn 


Curva- 




Line 












ture 




(Normal) 










Multipl 


y by Number of 


Add to 












Teeth 


in Spiral Gear 


P.D. 










2 


0.70710 


2.22142 


2.828 


1. 0000 


0.7854 


1.0785 


0.0785 


1.5708 


2\ 


0.62855 


1.97464 


2.828 


0.8888 


0.6981 


0.9587 


0.06^9 


1.3963 


2\ 


0.56566 


1.77707 


2.828 


0.8000 


0.6283 


0.8628 


0.0628 


1.2566 


2f 


0.51425 


1. 61556 


2.828 


0.7273 


0.5712 


0.7844 


0.0572 


I. 1424 


3 


0.47140 


1.48094 


2.828 


0.6666 


0.5236 


0.7190 


0.0524 


1.0472 


zh 


0.40406 


1.26939 


2.828 


0.5714 


0.4488 


0.6163 


0.0449 


0.8976 


4 


0.3535s 


1.11071 


2.828 


0.5000 


0.3927 


0.5393 


0.0393 


0.7854 


s 


0.28283 


0.88853 


2.828 


0.4000 


0.3142 


0.4314 


0.0314 


0.6283 


6 


0.23570 


0.74047 


2.828 


o.2,Z3?> 


0.2618 


0.3595 


0.0262 


0.5236 


7 


0.20203 


0.63469 


2.828 


0.2857 


0.2244 


0.3081 


0.0224 


0.4488 


8 


0.17677 


0.55S34 


2.828 


0.2500 


0.1963 


0.2696 


0.0196 


0.3927 


9 


0.15714 


0.49367 


2.828 


0.2222 


0.1745 


O.2307 


0.017s 


0.3491 


lO 


0.14143 


0.44431 


2.828 


0. 2000 ■ 


0.1571 


0.2157 


0.0157 


0.3142 


II 


0.12856 


0.40388 


2.828 


0.1818 


0.1428 


0.1961 


0.0143 


0.2856 


12 


0.11785 


0.37024 


2.828 


0.1666 


0.1309 


0.1798 


0.0131 


0.2618 


14 


O.IOIOI 


0.31733 


2.828 


0.1429 


0.1122 


0.1541 


0.0112 


0.2244 


i6 


0.08836 


0.27759 


2.828 


0.1250 


0.0982 


0.1348 


0.0098 


0.1963 


i8 


0.07855 


0.24677 


2.828 


O.IIII 


0.0873 


0.1198 


0.0088 


0.1745 


20 


0.07071 


0.22214 


2.828 


O.IOOO 


0.0785 


0.1079 


0.0079 


0.1571 


22 


0.06428 


0.20194 


2.828 


0.0909 


0.0714 


0.0980 


0.0071 


0.1428 


24 


0.05892 


0.18510 


2.828 


0.0833 


0.0654 


0.0898 


0.0065 


0.1309 


26 


0.05437 


0.17081 


2.828 


0.0769 


0.0604 


0.0829 


0.0060 


0.1208 


28 


0.05050 


0.1586s 


2.828 


0.0714 


0.0561 


0.0770 


0.0056 


0.1122 


30 


0.04713 


0.14806 


2.828 


0.0666 


0.0524 


0.0719 


0.0053 


0.1047 


32 


0.04425 


0.13901 


2.828 


0.0625 


0.0491 


0.0674 


0.0050 


0.0982 


36 


0.03929 


0.12343 


2.828 


0.055s 


0.0436 


0.0599 


0.0043 


0.078s 


40 


0.03533 


0.1 1099 


2.828 


0.0500 


0.0393 


0.0539 


0.0039 


0.0873 


48 


0.02944 


0.09249 


2.828 


0.0417 


0.0327 


0.0449 


0.0033 


0.0654 



In considering speed ratios for spiral gears the driving gear can 
be taken as a worm having as many threads as there are teeth and 
the driven as the worm wheel with its number of teeth, so that one 
revolution of the driver will turn a point on the pitch circle of the 
driven gear as many inches as the lead of the teeth of the driver. 



4S-DEGREE SPIRAL GEARS 



127 



Divide this by the circumference of the pitch circle of the driven gear 
to get the revolutions of the driven. 

While the subject of spiral gears is rather complex if considered 
broadly, most of the difficulties disappear when they have a tooth 
angle of 45 degrees. It is perhaps for this reason that from 75 to 90 
per cent, of the spiral gears used are made with this angle. 

This has the added advantage of being the most durable, although 
there is but a trifling increase in wear down to 30 degrees and the wear 
at 20 degrees is not serious. In cases of necessity even 12 degrees 
can be used without destructive wear. 

Where higher speed ratios than can be had with a 45-degree angle 
tooth are necessary, they can be laid out as will be shown later and 
can be cut on most milling machines. The usual change gears allow 
about two thousand different spirals to be cut. 

Where the angles are not 45 degrees, the gear with the greatest 
angle must always be the driver. 

All of the tooth parts are derived from the normal pitch while the 
pitch diameters are derived from the circular pitch. These are never 
the same in two gears of a pair except when both are 45 degrees. 

As the diameter of a spiral gear does not indicate its speed ratio, 
the terms driven and follower are used in place of gear and pinion. 

45-DEGREE SPIRAL GEAR 

These gears are the simplest of all spirals to lay out and to make, 
the required speed ratios being obtained by varying the diameters, 
precisely as with spur or bevel gears, the rules for the speed ratio 
being the same in both cases. Moreover, the various factors required 
in laying out and making such gears can be reduced to the simple 
table shown. 

Such a table has been worked out by E. J. Kearney. With it any 
one can quickly make the few calculations connected with any pair of 
45-degree gears having teeth between 2 and 48 diametral pitch. 
This table will be found on preceding page : 




128 



GEARING 



Example 

Let it be desired to construct a pair of spiral gears with 35 teeth in 
the gear and 16 teeth in the pinion, using a 10 pitch cutter. Using 
table on page 126 we have 

Pitch diameter = 0.14143 X 35 = 4-95o. 

Outside diameter = 4.950 + 0.200 = 5.150. 

Pitch in inches to one turn of spiral = 0.44431 X 35 = 15.550. 

Note. — A slight variation in one turn makes no practical dif- 
ference, hence the ordinary change gears furnished with a universal 
miller will usually be found sufficient. 

Number of teeth in spur with same curvature = 2.828 X 35 = 
98.980. 

Looking at B & S spur-gear cutter hst, we see that 99 is between 
55 and 134, therefore we select a No. 2 cutter. 

In a similar manner using 16 as a multiplier we obtain the data for 
the pinion. This gives 2.262 as pitch diameter so that the center 
distance = 4-95o + 2.262 ^ ^^^^^ 
2 



The Various Dimensions Follow 





Gear 


Pinion 


Number of teeth 


35 
4.950 
5-150 
15.550 
45 
10 
2 
0.216 

90 
3.6 


16 


Pitch diameter 


2.262 


Outside diameter 


2.462 
7.108 

45° 
10 

3 
0.216 


Pitch in inches to one turn 


Angle of spiral . . 


Pitch of cutter 

No. of cutter 


Whole depth of tooth 


Angle of shafts 





Center distance of shafts 


06 







FIGURING SPIRAL GEARS 

As there is no direct solution for a pair of spiral gears their 
calculation is a tedious process and the result must be found 
by trial. 

As numerous calculations are absolutely necessary, this formula 
should not involve division by large or fractional numbers and should 
contain the fewest possible operations. Such formulas are: 



Let 



Then, 



SPIRAL GEARS 129 

C = Center distance, 

P = Diametral pitch, 
iVi = Number of teeth in the driver, 
iV^2 = Number of teeth in the follower, 
Si = Spiral angle of driver, 
S2 — Spiral angle of follower. 



r — {sf^cdnt Si Ni) + {secant S2 N2) 

That is, the sum of the secant of the driving angle times the number of 
teeth in the driver, and the secant of the follower angle times the 
number of teeth in it divided by the diametral pitch equals twice the 
center distance. This formula is derived as follows: The secant of 
the spiral angle times the pitch diameter of a spur gear of the same 
number of teeth and pitch equals the pitch diameter of a spiral gear 
of that angle, the pitch of the spur gear being the same as the normal 
pitch of the spiral gear. Now for a spur gear the number of teeth 
divided by the diametral pitch equals the pitch diameter. Therefore, 

the secant of the spiral angle X — = the pitch diameter of a spiral gear. 

The combined pitch diameters times the center distance are equal to 

f Secant Si X — ) + f Secant S2 X — '") 

or (secant Si Ni) + (secant S2 N2) for one diametral pitch. 

The quantity secant Si Ni is the pitch diameter for the driver and 
secant S2 N2 is the pitch diameter of the follower. To obtain the 
center distance for any other pitch, it is simply necessary to divide 
this last result by that pitch. 

A table of secants will furnish constants covering the entire range 
of angles; and therefore, ail possible solutions for a pair of gears. 
After long experience in calculating spiral gears these are recommended 
by C. H. Logue as the best and simplest for all cases. 

Points to be Kept in Mind when Calculating Spiral Gears 

To assist in their use the following points should be kept in 
mind: 

1. The diameter of a spiral gear increases with its angle. 

2. Therefore, the diameter of the follower will reduce as the driving 
angle is increased, although not necessarily in the same ratio. 

3. It is quite possible for the center distance to remain practically 
constant through quite a range of angles, the follower decreasing as 
the driver is increased. This is especially true when the gear having 
the greater number of teeth is the driver. 



I30 GEARING 

4. If the center distance is too great when the driving angle is 45 
degrees — it must not go below that in any case — a lower number 
of teeth must be selected for both driver and follower, while main- 
taining the same ratio, and another trial made using a much higher 
angle for the driver. 

5. The center distance will increase with the angle of the driver. 
This increase is more rapid when reducing than when increasing the 
speed of the follower. 

6. The number of teeth selected for each trial must be in proportion 
to the desired ratio. 

7. Forty-five degrees is commonly accepted as the most efficient 
driving angle. 

Selecting Secants and Trial Numbers of Teeth 

To calculate a pair of spiral gears, select secants for the desired 
angles, assuming the normal pitch, try out the value of 2 C with trial 
numbers of teeth for driver and follower. 

If the value 2 C is too small increase the number of teeth and try 
again. A very few calculations will show the number of teeth to 
secure the closest result. 

If the center distance thus found is not as desired the angles must 
be shifted, keeping in mind the general laws governing the change of 
the center distance with the angle. 

It is often found that when the desired center distance is reached 
the driving angle is too large to be desirable. The only alternative 
is to change the normal pitch and try again. A shde rule will give 
approximate results. 

When there are limitations placed on the diameter of one or both 
of the gears the following formula is of value. It may also serve as 
a check on the above calculations. The pitch diameters are assumed. 



/ pitch diameter of driver X \ 
\numher of revolutions of driver) 



Tan. S\ 

(pitch diameter of follower X \ 
number of revolutions of follower.! 



This will set a limit on the driving angle Si, to exceed which means 
that the gear will be too large. 



SPIRAL GEARS 13 1 

REAL PITCHES FOR CIRCULAR PITCH 
SPIRAL GEARS 

The accompan>ang table will be found convenient in figuring 
particulars for spiral gearing, as it eliminates much of the work by- 
shortening the process, thus making it quite an easy and simple 
matter to find the dimensions for either helical gears with axes paral- 
lel to each other or for gears with right-angle drive. 

Formulas for use with the table are as follows: Circumference on 
pitch line = real pitch multiplied by number of teeth. 

Lead of Spiral = Circumference on pitch line divided by the tan- 
gent. 

Pitch Diameter = Circumference divided by 3. 14 16. 

For whole diameter add the same amount above pitch line as for 
spur wheels of the same pitch as the normal pitch. 

The following is an example of the use of the table: A pair of 
wheels is required to be: Ratio, 6 to i; normal pitch, i in.; driver, 
6 teeth; follower, 36 teeth; angle for driver, 66 degrees; angle for 
follower, 24 degrees. 

Referring to the table we find that the real pitch for the driver 
is 2.4585. 

2.4585 X 6 {teeth) = 14.751 {circumference on pitch line). 

Cir. 14.751 -^ 2.246 {tangent) = 6.567 {lead of spiral). 

Cir. 14.751 ^ 3.1416 = 4.695 {pitch diameter). 

For the follower the real pitch is 1.0946. 

1.0946 X 36 = 39.4056 {circumference). 

Cir. 39.4056 -h 0.4452 {tangent) = 88.512 {lead of spiral). 

Cir. 39.4056 -7- 3.1416 = 12.543 {pitch diameter). 

Another method of finding the lead of spiral is to multiply the 
real pitch by the number of teeth, but for this purpose take the 
real pitch of the mating wheel. 

In the above example we should have 

Real pitch of follower, 1.0946 X 6 = 6.5676 {lead of spiral). 

Real pitch of driver, 2.4585 X 36 = 88.506. 

It wiU be noticed that there is a slight difference in the result 
but this is unimportant, as it is only brought about by the dropping 
of a few decimal points in the tangent. 



132 



GEARING 



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Ml-,Ml-llHMMM^Hl-l<^^csc^c^MP^c^<^^c^c^cocococococococococotttttt 




O OcO i^O ui t CO M M O ooo t^O vo t CO cs m O OoO t~-0 lo t co M m °0 °Ooo °f^u5 "lo 
=0 t^r^r-t^r-t^t^t^r^ t^O OOOOOOOOO «r,ioioioio>oi/^ioioio 4 t t^ t 



134 



GEARING 



SPUR-GEAR CUTTERS FOR SPIRAL GEARS 



Number of Teeth in the Spiral Gear 

gsi§g s § § g; § 5S ^ s g KSEKtrs. 






s o 




|l!llli!i||t:l!lV l!;iMlini\':|i|!lNI ll \.r 


1 N KN 








^ 






_ 


^ 


















-n-iii" ;"""^ 


\J^aX N 










'4 


Mm s, "^ 


t \3.^ 














^ ^^ ^ 










:;:::::: r: 


s 


«> S ^ 












s 


Z%- \- X 




s. 






:::::::.__ _. i: 


t ^_ 


^J^ \ ^ 




s 








5' 's 


\ 


s 




. 






?? 


^ ~ ^^ 


\ 




\ 




. \L 


m 


-^- ^ 




s. 


s 




., S 


t£ 


V v 




\ 






1 


..It— 


-_\ 5 










i 


ra ti 


^^ 


\ 




\ 


o 


!Mi|!MIIIIIIIIIIIII 




\ 




^ 




.., ■ ■ , L 


H'l 


■^ 




\ 






•: ' ^i—rf 


W V 


~~' S 




\ 






: iV, ! iiii 1 V. 


'~~' \ 






\, 


g 

o 


il i 1 "^-11 s 


\ 






\ 


^! %] ---,---- 


^ 










111 <; 

111 1 V 




\ 








jl ::::::::;::::::^; 






\^ 








\ 




\ 






^1 I 


s 






\^ 





II 


\ 










i 


"'" \ 










l! 














\ 








o 




\ 








o 






\ 















\ 














\ 




i 1 . 1 








s 





To find the number of a spur-gear cutter to be used in cutting a given 
spiral gear, locate the intersection of lines traced from the points 
representing the number of teeth and the spiral angle on the two 
scales. The number in the area on the chart within which the inter- 
section falls is the cutter number of Brown & Sharpe's involute cutter 
system required. 



SPIRAL GEAR TABLE 135 



SPIRAL GEAR TABLE 

While it is better in every case to understand the principles in- 
volved before using a table as this tends to prevent errors, they can 
be used with good results by simply following directions carefully. 
The subject of spiral gears is so much more complicated than other 
gears that many will prefer to depend entirely on the tables. 

This table gives the circular pitch and addendum or the diametral 
pitch and lead of spirals for one diametral pitch and with teeth hav- 
ing angles of from i to 89 degrees to 45 and 45 degrees. For other 
pitches divide the addendum given and the spiral number by the 
required pitch and multiply the results by the required number of 
teeth. This will give the pitch diameter and lead of spiral for each 
wheel. For the outside diameter add two diametral pitches as in 
spur gearing. 

Suppose we want a pair of spiral gears with 10 and 80 degree angles, 
8 diametral pitch cutter, with 16 teeth in the small gear, having 10- 
degree angle and 10 teeth in the large gear with its 80-degree angle. 

Find the lo-degree angle of spiral and in the third column find 
1.0154, Divide by pitch, 8, and get .1269. Multiply this by num- 
ber of teeth — .1269 X 16 = 2.030 = pitch diameter. Add 2 
pitches — two i = J and 2.030 + .25 = 2.28 inches outside diameter. 

The lead of spiral for 10 degrees for small wheel is 18.092. Divide 
by pitch = 18.092 -^ 8 = 2.2615. Multiply by num^ber of teeth, 
2.2615 X 16 = 36.18, the lead of spiral, which means that it makes 
one turn in 36.18 inches. 

For the other gear with its 80-degree angle, find the addendum, 
5.7587. Divide by pitch, 8, = .7198. Multiply by number of 
teeth, 10 = 7.198. Add two pitches, or .25, gives 7.448 as outside 
diameter. 

The lead of spiral is 3. 1 90 1. Dividing by pitch, 8 = .3988. Multi- 
plying by number of teeth = 3.988 the lead of spiral. 

When racks are to mesh with spiral gears, divide the number in 
the circular pitch columns for the given angle by the required dia- 
metral pitch to get the corresponding circular pitch. 

If we want to make a rack to mesh with a 40-degree spiral gear 
of 8 pitch: Look for circular pitch opposite 40 and find 4. loi. Divid- 
ing by 8 gives .512 as the circular pitch for this angle. The greater 
the angle the greater the circular or linear pitch, as can be seen 
by trying an 80-degree angle. Here the circular pitch is 2.261 
inches. 



136 SPIRAL GEAR TABLE 

SHAFT A1-3GLES 90° FOR ONE DIAMETRAL PITCH 





^1 

•Eg 


diameter, 
diametral 
: quotient 
■r.of teeth 






diameter, 

diametral 

quotient 

r of teeth 


^1 




s 


u,-a 


^ifl 


To obtain the lead of 




u^ 


w 




3 ^ 


spiral, divide by the 


-1^ 

3-^ 


& 


^"S 


•H-'i-'E i 


required 


diametral 


Q 


Q 


o^ja 


m 


pitch and multiply 


?2tJ 


■S'2-a 


a 


H 


u > " 


quotient by the re- 


l|il 


ii.^H 


•S 


•R 


■S'S'S, 


quired 


number of 


1-3-S, 


1 


w 

•s 


cfg 


5 '^ a 


teeth 




■ml 


•111 


'cl 




III 
o-v 








nn 

0^ 5^ 


o-o 


5P 


h 


h 






H 


h 


< 




Circular 
Pitch 


One 

Tooth or 
Addend 


Lead of Spirals 


One Tooth 

or 
Addendum 


Circular 
Pitch 




Small 


Small 


SmaU 


Small 


Large 


Large 


Large 


Large 


Wheel 


Wheel 


Wheel 


Wheel 


Wheel 


Wheel 


Wheel 


Wheel 


I 


3-1419 


l.OOOI 


180.05 


3-1420 


57-298 


180.01 


89 


2 


3.1435 


1 .0006 


90.020 


3-1435 


28.653 


90.016 


88 


3 


3-1457 


I.00I3 


60.032 


3-1458 


19.107 


60.026 


87 


4 


3-1491 


1.0024 


45-038 


3-1492 


14-335 


45.035 


86 


5 


3-I53S 


1.0038 


37-077 


3-1527 


11-473 


36.044 


8S 


6 


3-1 5S9 


1-0055 


30.056 


3-1589 


9-5667 


30.055 


84 


7 


3-1652 


1.0075 


25-728 


3-1651 


8.205s 


25-778 


83 


8 


3-1724 


1.0098 


22.573 


3-1724 


7.1852 


22.573 


82 


9 


3.1806 


I.OI24 


20.0S2 


3-1807 


6.3924 


20.082 


81 


10 


3.1900 


1. 01 54 


18.092 


3-1901 


5-7587 


. 18.092 


80 


11 


3.2003 


1.0187 


16.464 


3-2003 


5-2408 


16.464 


79 


12 


3-2145 


1.0232 


15.076 


3-210S 


4-8097 


15.104 


78 


13 


3.2242 


1.0263 


13-966 


3.2294 


4-4454 


13-988 


77 • 


14 


3-2377 


1 .0306 


12.986 


3-2378 


4-1335 


12.986 


76 


IS 


3-2522 


1-0352 


12.138 


3-2524 


3-8637 


12.138 


75 


16 


3.2679 


1 .0402 


11-393 


3-2678 


3-6279 


11-397 


74 


17 


3.2848 


1.0456 


10.417 


3.2821 


3-4203 


10.745 


73 


18 


3-3116 


1.0514 


10.192 


3-3032 


3.2360 


10.166 


72 


19 


3-3225 


1.0576 


9-6494 


3-3225 


3-0715 


9.6494 


71 


20 


3-3430 


1. 0641 


9.1848 


3-3433 


2.9238 


9.1854 


70 


21 


3-3650 


1.0711 


8.7662 


3-3652 


2.7904 


8.7663 


69 


22 


3-3882 


1.0785 


8.3862 


3-3833 


2.6694 


8.3862 


68 


23 


3-4127 


1.0863 


8.0309 


3-4129 


2-5593 


8.0403 


67. 


24 


3-4061 


1.0946 


7-7379 


3-4391 


2.4585 


7.7242 


66 


^1 


1-1033 


7-4332 


3-4663 


2.3662 


7.4336 


65 


26 


3-4953 


1.1126 


7.1664 


3-4952 


2.2811 


7.1663 


64 


27 


3-5258 


1. 1223 


6.9198 


3-5257 


2.2026 


6.9197 


63 


28 


3-5579 


1-1325 


6.6912 


3-5575 


2.1300 


6.6916 


62 


29 


3-5918 


1-1433 


6.4799 


3-5919 


2.0626 


6.4799 


61 


30 


3-6276 


I -1 547 


6.2778 


3.6277 


2.0000 


6.2832 


60 


31 


3-6650 


I. 1666 


6.0979 


3-6652 


1.9416 


6.0997 


59 


32 


3-7043 


I. 1791 


5-9282 


3-7044 


1.8870 


5.9282 


58 


33 


3-7457 


1.1923 


5.7710 


3-7459 


1.8360 


5-7680 


57 


34 


3-7894 


1.2062 


5.6181 


3-7826 


1.7882 


5.6178 


56 


35 


3-8349 


1.2207 


5-4754 


3-8351 


1.7434 


5-4770 


55 


36 


3-8830 


1.2360 


5-3431 


3-8834 


1.7013 


5-3448 


54 


37 


3-9336 


1.2521 


5.2201 


3-9261 


1.6616 


5.2200 


53 


38 


3-9867 


1.2690 


5.1028 


3-9921 


1.6242 


5.1026 


52 


39 


4.0482 


1.2867 


4.9866 


4.0416 


1.5890 


4.9920 


51 


40 


4.1010 


1-3054 


4.8873 


4.1012 


1-5557 


4.8874 


50 


41 


4.1626 


1.3250 


4-7885 


4-1540 


1.5242 


4.7884 


4? 


42 


4-2273 


1-3456 


4-6949 


4.2272 


1.4944 


4.6948 


48 


43 


4-2956 


1.3673 


4.606s 


4.2956 


1.4662 


4.6062 


^1 


44 


4-3671 


1.3901 


4-5223 


4-3675 


1-4395 


4-5225 


46 


45 


4-4428 


1. 4142 


4.4428 


4.4428 


1.4142 


4.4428 


45 



THREADS OF WORMS 137 



THREADS OF WORMS 

Worms are cut with threads having a total angle of 29 degrees, 
similar to the Acme thread. Some use the same proportions as for 
the Acme, but most use a deeper thread such as the Brown & Sharpe, 
which is .6866 deep instead of .51 for a one-inch pitch as in the Acme. 
It is not easy to cut odd fractional pitches in most lathes-, so regular 
pitches are cut and the circular pitch of the worm wheel is allowed 
to come in fractional measurements for pitch diameters and center 
distances. Having determined on the reduction as 40 to i, the rel- 
ative proportions can be considered as follows: 

Assume a thread of 4 to the inch for the worm or a lead of I inch. 
Then as the reduction of 40 to i there must be 40 teeth in the worm 
gear, I inch from center to center of teeth or 10 inches in circum- 
ference on the pitch line or 3.18 inches. If a reduction of 20 to i 
is wanted we can use the same gear but cut a double thread of 2 per 
inch, which will give the same distance between teeth, but the worm 
gear will be moved two teeth every revolution of the worm. 

Some of the commonly used proportions are: 

_,.,,. r No. of teeth X pitch in inches 

Pitch diam. of worm gear = ^ . 

3.1416 

T^- 1-1 ^.1416 

Diametral pitch = — r^ : — 7. 

Linear pitch 

Throat diam. of worm gear = Pitch diam, 4- ttt tt^tt.' 

^ Diam. Pitch 

Outside diameter of gear for 60° sides = throat diameter + 2 (.13397 
throat radius.) 

Whole depth of tooth of worm or worm gear «= .6866 X lineal 
pitch. 

Width at top of tooth of worm = .335 X linear pitch. 
Width of bottom of tooth of worm = .31 X linear pitch. 
Outside diam. of worm — single thread = 4 X linear pitch. 
Outside diam. of worm — double thread = 5 X linear pitch. 
Outside diam. of worm — triple thread == 6 X linear pitch. 
Face of worm gear = ^ to f outside diameter of worm. 



Width of Face 

A COMMON practice for determining the width of face or thickness 
of worm wheels is shown in Fig. 15. Draw the diameter of the 
worm and lay off 60 degrees as shown; this gives the width of work- 
ing face, the sides being made straight from the bottom of the teeth. 
Others make the face equal to f the outside diameter of worm, but 
^ the diameter of the worm is more common. 



138 



GEARING 




THREADS OF WORMS 



139 



Table of Proportions of Worm Threads to Run in Worm 
Wheels 



B. 

Width of 
Thread 
at Top 


CQ 


00 M lOl-^O N fOU^O r-r^oo -^Ooo OOP) inO>0.0>vO 
t^OO " fOi'lN'O fO" 000 t^O iO-*5-fOrOP) M " 

vq -> lo -3- CO CJ CJ « M M q q q q q q q q q q q q q 


W. 

Width of 

Thread 

Tool 
at End 


II U 


»o »n >^^ foo >o a t^ <ooo ■* 00 w ■* <N 

N TTvOOO " COO i^<N 000 r^OO VOtcococON C) M p- 

«q lo ^ CO CO cs (N M M « q q q q q q q q q q q q q 




^:s^ ;j II 


OOOOOOcoOO^OC^OMOcot•J^loo^OI^Ml^. 
OJOO'OOJOcoOOOn^MOco^nLoo^^iOMVr. 

^coiCsq SiJ^^oJ^S^, MM M 2^^ q^ q q q q q q 


W.D. 

Whole 

Depth of 

Tooth 


^0 


PI Ov co^O r^ co^O 00 NOVO fO-<tM00 coi^ei Ot^ 
CO M Ovoo ^o 10 r- CO ^00 " t^ -^00 lovo 00 r- Ov M r- 
l^ <N 1000 M lorft^oi Or^iocOM OvOO t^O >o "^ ■^ co 

coc^qoO'Oio^coiNc^MMMMMqqqqqqqq 


S. 

Depth 

of Space 

below 
Pitch Line 


u 

+ 


\O>O»O'<tcON»ONCOl^MH00r~ 'I-VO O OOO t- CO O w 
^P) O00<3 lOTt-r^CN IOCS m com mO OO 0>0 coo 
CO rr too vO t^ rroo ^ cm OvOO r-vO lOTf-^cococN (N N 

r-vq '^t'?"^". ':i". ". ^OQQQoqqqqqq 




C. 

Clearance 


Hi2 


0>00>00»OCOOOOCO>OwOCOw<v)lr-, 0<nOmio 

00 r-O Lococo cm' (NmmmmmOGDo' 00000 

Mqqqqqqqqqqqqqqqqqqqqqq 


D. 

Working 

Depth 
of Tooth 


X 

II 

Q 


p) M aoo vo V-, n- co>o cs om v>cow o^ot^i^o -^oo P) 
CO -^ Tt 100 r~ TToo M- P) M ov M r-o M 00 CO CO i^, o> I'-. 
r^M loocot^p) M liiMoo i'^ -^ ct Of-r^O lo^^roco 
(N M q> t^^q f f ^ fj <^. ". ". « « ►: q q q q q q q q 


H. 

Tooth 
above 
Pitch- 
Line 


Oh* 
II 


vo o>oo>coi^N p) cow oo 1^ r- M 1000 -^oo »o r- Ov\o 

VO t^ 1^ t^OO 00 M Ov t^vO 0.0 COCOlOOitOMMS P) 0>J^ 

coiot-o>MCOMU^P)oar- riv3 lo^cococop) pg m m 
vqio'j-cocopjcHMMMqqqqqqqqqqqqq 

■ 


D. P. 

Dia- 
metrical 
Pitch 


II 

a.' 
Q 


00 P> ^ covO COtP)OoOO'*P)0>OwI^coO>PiTr tooo 
lOTfcOMOO P) CO-*-* "-<-0 r-00 0. M P) Tt to P) u-,00 
t^ Ov M -^i-oo M 00 10 P) 00 CO •* CN CO r- M 000 ^ 
ioi--q lOM M ^^c^oq "^ o^ ";> ", ^co q> « pj ^^ 9 <^ 'C- 
M M ci M CO ■* -*vd r^ Ov 6 PJ 4 >oo6 M >A,od M r^ CO 6 

„MMMMP<P<P)COCO-<riOlA, 


pi. 
Threads 


•a 


r^.I*>«t!-5'«0 HC-!-«M .-«?» .-tN rJCJ 

MMMNPtCOPO'^-* 10*0 t>.00 Oi M '*\0 00 


C.P. 

Circular 
Pitch 




C „ M M M 



o9 



^ ^ 


. ^ 


•y-^ 


"2 "^-5 










^ ^ 


^-s 


-o <u 


>> -2 


It 


deb 

24. 

plus 















^ «-i (U 3 'T1 



rt o 



1) CJ 









^ E -^ a; ^ ^• 



Sill I I 



I40 



GEARING 



SPEEDS AND FEEDS FOR GEAR CUTTING 

(Cincinnati Gear Cutting Machine Co.) 

Range of dififerent sizes of machines as follows : 

No. 3. Up to and including 4 diametral pitch. 
No. 4. Up to and including 3 diametral pitch. 
No. 5. Up to and including 2 diametral pitch. 
No. 6. Up to and including if diametral pitch. 
No. 7. Up to and including i diametral pitch. 

For Carbon Steel Cutters RxJN>riNG at a Peripher.\l Speed of 35 Feet 
PER Minute on Cast Iron and 30 Feet per Minute on Steel 



^ 




1 


Feed in In. per Min. 




a 


Feed in In. per Min. 


for Roughing Cut 


Feed in In. per Min. 


(^ u 


Finishing in one 


Cut 


.010 to .030 in. Left for 


for Finishing Cut 


■gS 






Finishing Cut 






Cast 


Soft 


High 
Car- 


Nick- 
el 
Steel 


Cast 


Soft 


High 

Car- 


Nick- 
el 
Steel 


Cast 


Soft 


High 
Car- 


Nick- 
el 
Steel 




Iron 


Steel 


bon 
Steel 


Iron 


Steel 


bon 
Steel 


Iron 


Steel 


bon 
Steel 


I 






I 8 


I - 


I 


I 


2lV 


I 1 


If 


li 


I* 










I f 


I - 


I 


I 


2t^, 


I 8 


If 


I 4 


li 










2t^ 


I - 


li 


I 


2fA 


2lV 


21^. 


I 


if 


2A 


in 


It". 




3^ 


2ik 


2t^« 


lU. 


4-^ 


3s 


2H 


2t'. 


2 


2 2 


2 


lik 


li 


4tV 


3i 


2h 


2 


4t^« 


3 i 


2 1 


2 


2^ 


2 ^ 


2 


iH 




4A 


3i 


2^ 


2 


4i^ 


3i 


2 i 


2 


3 


,^T^ff 


2 - 


a 


4i^- 


3t'r 


2 


2 


45 


3t'. 


2 5 


2 


4 


3t'«- 


2 ^ 


2 


if 


'^f 


3i;6- 


2 


2 


4 ^ 


318 


2 i 


2 


5 


.St'b 


2 ^ 


2 


^t 


3i'rt 


2 - 


2 


44 


3ts 


2 ^ 


2 


6 


3A- 


2 ^ 


2 


I 


4i 


3/s 


2 - 


2 


4 4 


3l'5 


2 *■ 


2 


7 


.StV 


2 ^ 


2 


4i 


3A 


2 ^ 


2 


4i 


3Trt 


2 - 


2 


8 


3t'« 


2 - 


2 


i| 


.St's 


4 s 


3/5 


2* 


.St'b 


4- 


3/e 


2 - 


9 


4i 


3t'. 


2 1 


2 


5t'« 


4z 


3T'fl 


2i 


.St'. 


4- 


3/5 


2 - 


10 


4 i 


3t's 


2 2 


2 


Si'e 


4i 


31^. 


2^ 


Si'. 


4 - 


3Tff 


2 ^ 



For High Speed Steel Cuttebs Running at a Peripheral Speed of 55 Feet 
PER Minute on Cast Iron and 80 Feet per Minute on Steel 



rt 


■ 


Feed in In. per Min. 




W 


Feed in In. per Min. 


for Roughing Cut 


Feed in In. per Min. 


(^ !d 


Finishing in one Cut 


.010 to .030 in. Left for 


for Finishing Cut 


IS 




Finishing Cut 




Cast 


Soft 


High 
Car- 


Nick- 
el 
Steel 


Cast 


Soft 


High 
Car- 


Nick- 


Cast 


Soft 


High 
Car- 


Nick- 
el 
Steel 


Q 


Iron 


Steel 


bon 
Steel 


Iron 


Steel 


bon 
Steel 


Steel 


Iron 


Steel 


bon 
Steel 


I 










2 


If 


If 


I ? 

I 8 


2^ 


2H 


2}.^ 


2 IB 


Is 










2 - 


2 


2 


3tHt 


3tH. 


3t^t 


2H 


i^ 










3 ^ 


2t^ 


2,^ 


2l^ 


4f 


4f 


4^ 


3 f 


I* 


2H 


2t\ 


2t^« 


iH 


4- 


3f 


3l 


2ii 


Sr'k 


Sf-. 


.SfH 


4f 


2 


3i 


2 2 

2 8 


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si 


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44 


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87 



MILLING AND MILLING CUTTERS 



MILLING MACHINE FEEDS AND SPEEDS 

The determining of the proper feeds of milling cutters in the past 
was usually a matter of guesswork, or experience, as a good many 
would term it, no absolute rule of any kind having ever been 
established. 

A guide for determining the proper feed of milling cutters is found 
in ascertaining the thickness of the chip per tooth of the cutter. 

Taking, for example, an average size milling cutter working in 
cast iron, say 2§ inches diameter, 3 inches long, with eighteen teeth, 
which is quite commonly used, and it will be found that the thick- 
ness of the chip per tooth is quite small, resulting in .0018 inch, with 
a table feed of 2 inches per minute. This is entirely too slow. Now, 
comparing this cut of .0018 inch with a lathe tool cut, it will be seen 
that such a chip in a milling cutter is much smaller and is far more 
injurious to the cutter than a heavier feed, since the cutting edge of 
a tool will hold up longer in cutting into the metal instead of scrap- 
ing it. 

A cutter is very seldom ruined by the feed, but is generally ruined 
by overspeeding it. For instance, with a cutter of thirty teeth with a 
table feed of .300 inch per revolution, the chip per tooth will then 

.300 
only be — j^ = .010 inch thick — still quite a light cut when compar- 
ing it with a lathe tool chip. Hence in many cases of milling, if the 
feeds are guided by the thickness of chip per tooth, a much faster 
feed would be used, since it is evident that the heaviest feeds, com- 
aratively, give only a thin chip per tooth. 



Cutting Speeds 

The Brown & Sharpe Mfg. Co. recommends a cutting speed of 65 
feet per minute for carbon and 80 to 100 feet per minute for high 
speed milling cutters under average conditions. On soft cast iron, 
having a tensile strength of about 13,000 pounds — the feed recom- 
mended is 0.148 inches per revolution or about 9 inches per 
minute for carbon cutters. With a medium cast iron of about 
23,000 pounds tensile strength, the same speed is maintained but 
the feed reduced about f or to 6 inches per minute. For high speed 
cutters the feed can run up to 0.26 inch per revolution on the softer 
iron. 

141 



142 MILLING AND MILLING CUTTERS 

On steel of 65,000 tensile strength, with a cut 6 inches wide by y\ 
inch deep, a feed of 16 inches per minute can be maintained for long 
periods. At 60 revolutions per minute and a feed of 0.262 per revo- 
lution 18 cubic inches per minute was removed with 21 horse- 
power. 

It is not always advisable to maintain the highest cutter speeds as 
a slower speed and heavier feed will prevent vibration and chatter. 
These are not maximum results but. can be attained under regular 
working conditions. The horsepower required for removing a cubic 
inch of metal per minute on the milling machine may be safely con- 
sidered as if horsepower for steel and f horsepower for cast iron. 



The Action of a Milling Cutter 



Experiments carried on with cutters at the works of the Cincinnati 
Milling Machine Company and extending over several years, have 
led to results of general interest. These tests covered milling cutters 
of various types. 

The action of the ordinary milling cutter is not a true cutting 
action, as it is commonly understood. By a true cutting action is 
meant the driving of a wedge-shaped tool between the work and the 
chip and, although this definition is not based on a generally accepted 
meaning of the term, it is believed that it expresses fairly well what 
most mechanics understand by cutting. Practically all milling 
cutters have their teeth radial and this, of course, excludes the possi- 
bility of driving a wedge between chip and work. The tooth com- 
presses the metal until it produces a strain great enough to cause a 
plane of cleavage at some angle with the direction of the cutter. It 
then begins to compress a new piece, push it off, and so on. This at 
least seems to be the action of the cutter, judging by the form of the 
chips. These chips are in the form of needles or small bars. 

The chip taken by a milling cutter varies very materially from 
those taken by a lathe or planer tool. These latter tools make chips 
of uniform section, whereas the section of a milling chip increases 
from zero to a maximum. 

Fig. I shows a milling chip as it would appear, if no compression or 
distortion took place. The proportions are very much exaggerated, so 
as to bring its typical shape clearer into view. The width A B at 
the top is equal to the feed per tooth. The height B Cis the depth of 
cut. The length B D is the width of cut. The section M N P, 
shown halfway on the chip, is a normal section and a measure of the 
amount of work which was done at the time the cutter passed the 
point M. 

Fig. 2 shows the action of a milling cutter, with center 0, when the 
cutter is rotating and the work is feeding at the same time. The 
tooth A B sweeps through the path B C. When the point B has 
reached the position Bi, a new tooth starts cutting. By this time O 
has advanced to position O2, and the new tooth A2 B2 is not yet in a 
vertical position, when the point B2 touches the work. When the 



ACTION OF CUTTER TOOTH 



143 



cutter revolves, this point B2 must penetrate into the work and com- 
press the metal of the work. The result will be spring in the arbor. 
When this spring has assumed certain proportions, the blade or tooth 




Fig. I — Chip As- Fig. 2. — Action 
sumed to be pro- of Milling 
duced by Cutter Cutter 
without distortion 



Fig. 3. — Coarse pitch 
Milling Cutter 



begins to remove a chip. This may be assumed to take place in the 
position Bz, the tooth simply gliding over the work from B2 to Bz. 
This action must necessarily be very harmful to the cutter, and it 
was believed that this, perhaps more than any other action of the 
cutter, caused its dulling. It would be especially severe with hght 
cuts, as a relatively small amount of spring would allow the point 
B2 to travel through a large arc. It would be quite possible that a 
tooth should fail entirely to take a chip, and that the succeeding tooth 
would take a chip of double the amount. 

This peculiar action of the milling cutter is inherent in its con- 
struction and cannot be avoided. This question then is how to 
minimize these harmful results. 

Another feature, which limits the ability of a milling cutter to 
remove metal, is the proportion between the chip to be removed and 
the amount of space between two adjoining teeth. Such a limitation 
does not exist with lathe or planer tools, where the chips have un- 
limited space in which to flow off. 

Form of Tooth in the New Cutter 

The foregoing considerations led to a gradual evolution of spiral 
milling cutters. At first, the number of teeth of spiral mills was only 
slightly diminished, as it was thought that some element which was 
not considered might aflfect the result. Gradually the spacing was 
increased and the cutters, as now used, have taken the forms shown 
in Fig. 3. 

Two standard sizes are used, although other sizes are required for 
special cutters and special gangs. The standard diameters are 3I 
inches and 4^ inches. The 3|-inch diameter cutters are made with 
nine, and the 4^-inch diameter cutters with ten teeth, which corre- 
sponds to a spacing of about i\ inches. The point of the tooth has a 
land of 3V inch, and the back of the tooth forms an angle of 45 degrees 
with the radial line. The chip space is approximately four times as 
great as in the usual standard cutter of the present time and is formed 
with a y\-inch radius at the bottom. 



144 



MILLING AND MILLING CUTTERS 



Results of Tests 

Very satisfactory results were obtained with these cutters. Figs. 
4, 5, and 6 show the results of tests made with cutters mth |-inch, 
■f-inch and i|-inch spacing. Cuts were taken on cast-iron test 



14 

IS 

I 10 





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2 4 6 8 10 12 14 16 
Feed, Inches per Minute 



2 4 6 8 10 18 14 16 13 
Feed, Inches per Miaute 



2 4 e 8 10 12 14 le 18 
Feed, Inches per Minute 



Milling Cutters and their Efficiency 



blocks. It will be noticed that the same amount of power is required 
to take a cut j-inch deep and with 10.4 feed with a cutter of |-inch 
pitch, and a cut \ inch deep and with 13.5 feed but with a cutter 
1 1-inch pitch. 

Therefore there is a large increase in the amount of metal which 
can be removed with the same amount of horsepower, by using these 
wide-spaced cutters. It was also found that for roughing on the ordi- 
nary work in the shop a cutter with the wider-spaced teeth would 
remain sharp for a longer period, notwithstanding that feeds had been 
increased. 



The Finish of the Work 



It is a common belief that better finish can be obtained with teeth 
closely spaced, but experience with the wide-spaced cutter shows that 
there is no ground for this belief. The grade of finish may be ex- 
pressed by the distance between successive marks on the work. These 
marks are revolution marks and not tooth marks. It is practically 
impossible to avoid these revolution marks. They are caused by 
the cutter not being exactly round or quite concentric with the hole, 
by the hole not bemg of exactly the same size as the arbor, by the 
arbor not being round, by the straight part of the arbor not being 
concentric with the taper shank, by the taper shank not being round 
or of the same taper exactly as the taper hole in the spindle, by this 
taper hole being out of line with the spindle, by looseness between 
the spindle and its bearings, etc. Each of these items is very smaH 
in any good milling machine; yet the accumulation of these Httle 
errors is sufficient to cause a mark, and this mark needs to have a 
depth of only a fraction of a thousandth of an inch to be very plainly 
visible. As these marks are caused by conditions which return once 
for every revolution of the cutter, it is plain that the spacing of the 
teeth can have no effect on the distance between them and, therefore, 
Qn the grade of finish. This has been proven by actual tests. 



TAPER SHANK END MILLS 



145 



The Chip Breaker 
It is generally believed that for finishing alone a milling cutter 
should be used without chip breakers, the effect of the chip breaker 
being to scratch the surface. To overcome this trouble, chip break- 




ID R.H. Spiral 8 Teeth ^./[^ j 

Fig. 8. — Taper Shank End Mills 



ers are made as shown in Fig. 7 with clearance at both corners. This 
prevents the tearing up of metal with the result that a cutter with 
these chip breakers produces as good a finish as one without chip 
breakers. 

End Mills 

Fig. 8 shows the end mills which are now considered standard by 
the Cincinnati Milling Machine Company and which fill practically 
all requirements. They are made in sizes of i inch, i^ inches, i^ 



146 



MILLING AND MILLING CUTTERS 



inches and 2 inches in diameter, the smallest with four, and the 
largest with eight teeth. In order to preserve the strength of the 
teeth it is necessary to mill the back of the teeth of the three smaller 
sizes v/ith two faces. Their action is remarkably free. A 2-inch 
taper shank end mill milled a slot ixV inches deep in a solid block 
of cast iron at a rate of 6 inches per minute. The block was 




Spiral Shell Cutters 



clamped to the table of the milling machine and the knee was fed 
upward. The same cutter would remove from the end of the casting 
a section i| inches wide and i| inches deep. Under the latter con- 
ditions, the chips would free themselves from the cutter and these 
chips were rolled up in pieces much like the chips obtained from a 
broad planer tool, when taking a finishing cut. This cut was taken 
with a feed of 1 1 inches per minute. Another similar cut, but i inch 
and 1 1 inches in section, was taken with a feed of ^s inches per 
minute. 



SHELL END MILLS 



147 



Fig. 9 shows the shell end mills of the wide-spaced type, which 
are now considered standard for their use by the Cincinnati Milling 
Machine Company, and Figs. 10 and 11 show the side mills. 




'/32'' 6' Diam. 

- Side Mills 



When milling steel, a heavy flow of oil on a milHng cutter, forced 
by means of an oil pump, is just as essential as the great volume of 
oil which is used on automatic screw machine tools, which would 
not hold up one-half hour if not so flushed. The life of a milling 
cutter amply lubricated will be materially prolonged and it will be 
capable of standing a much heavier feed. 



Tan a 




Leads or B. & S. Cutter Spirals 

The leads of the Brown & Sharpe Cutter 
Spirals are as follows: 



Tan a = 



Diam. of Cutter 


Lead 


Diam. of Cutter 


Lead 


h" 


7.29" . 


2" 


31.5" 


f- f" 


9-52" 


2i-2|" 


36" 


i" 


13-71" 


2f-3" 


48" 


I -li" 


17.14" 


2>h-2>\" 


60" 


n" 


23-33" 


a" 


68.57" 


If" 


28" 







148 



MILLING AND MILLING CUTTERS 



j.^-Q (t>s rt 



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pnjs uo JB30 jsjjj 



uuo^ uo.«aO 



TABLE OF PITCHES AND ANGLES 149 









vo -^ -^ 
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10 W 04 N 

Tt- rt -^ T^f- 


't fO 0) OS On 
^ '^ -^ -* <^ ro 


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■*-d-'^tr>rorOt~OrorOrooi cs <M ci N M cs 


ro w OnO rOO) M OCOCO t^LO'-^fOC) M O O 
rf'^rofOrOfOrOrorotN w <N N M (n N C) cn (N 


^0 t^iJ-i (^ r^O Lo to ro cs w CnOO 00 t^ t^vO 
-d-TfrOrOrooorOr^N (N Cl C4 (NO) 0) 0) w M M M m m 


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^TfTl-OOrOrOrOOI040)01040)0«OIO)i-lMI-fHMMMM 


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xi-CO 04 Geo 04 TO CM:^ fONO ro^N 0400 r^ONM 04 roO ^OO^ OnI^O 
M 04 N 04 04 04' oOPOro444iO iA.NO* NO no' NO !>. i>. l>.oo' On On On 0' 6 O* 

M M H 


0404040404040l0404-^W04«04-^0»04NO"^NVO04Tt04NONO04'^ 

t^t^t^r-^f^t^t^t^ r^NO t^ t^ t>» t-*NO t^ t^ vono t^ 10 r^vO i>. lo lo t^vO 


00 OOOOOOONOOO N rtOO COnOo^oOOONOOOOOnO ^00 a NO NO 
04 ■<!i-01 •<^0» ir>0« OTJOJ ^^04 mcON <N fO-^W •^•>!l-00'^<N4 rt "^ en u^ m 


rt"*NO Ti-NO ^OOCOOO 0100 ^0 00000000000 04 000000 
NO NO tDNO 10 NO rtTl-^t^^NO '^'^rt'-^t'^'^rl-'^'^rOOD'^'^'^'^t'^ 


01 T04 Tl-O TfO QNO QNO OOOnOnOnOnO ^nO ^ '^OO 04 NO ^ 04 rfoO 
CON rO04 ^M ^'^LOrl-tO'^-^W-JVOlO LDN© VONO n© Tj- t>. u-jN© t^NQ -^ 



ISO 



MILLING AND MILLING CUTTERS 



U 



To find the angle for cutters of a larger diam- 
eter than given in the table, make a drawing as 
shown in the diagram; the angle b being a right 
angle. Let b c equal the circumference. Let a b 
equal the pitch. Connect c a by a line, and 
measure the angle a with a protractor; or divide 
^ the circumference by the lead and the quotient will 
be the tangent of the angle. Find the angle in a 
table of tangents. 


Diameter of Mill, Cutter, or Drill to be Cut 

Inches 

Values Given Under Diameters are Angles in Degrees 


T^ 










5^ 




Tt- Tt ^ Tt 


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M M M H 


HQO 


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M M H H 


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TABLE OF PITCHES AND ANGLES 151 



CT) t^ C^ On OnOO 00 CO ro 0) C) OnOO lo uo •rj- 


MhiiHl-* 
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CM CM M M 


to 


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M O 


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t-~ 

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t-- "^ po o) 

N <N N <N 


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CM CM M M 




MHMlni 
CO CM 
M M 


MM 

M On 




NO 


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(N W OJ CM 


ON ON !>. lO PO fO C< 

M M M M M M M 


H-* 
O On 

M 


H-*M|-*HC^HlN iHb* rHH<M|-*rtK^ HCl r^P^ rtl^l rt|C^ Hc^ r-l-<il r^^^^ coH' 

■«^rororOfOrOfOrorOCSC40»W<NC»cscq(N<NMMMMH 


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01 M ONOO 
M M 


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rOCOrOrororOrOM <N (N n (N M N (N 


MN-hIOMItK 

<N ON O-.00 
CM H M M 


M M M M 


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M M 


a.oo 


MI^tHHi Wh^rHlC^ Ml-* Ml^ .05|'*1MN 

u-> r^ ro <N ON 000 t^O lO "^ fO fO (N 
rOfOrO«T><N<M0)CS<NNWC^WCS 




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CMHMMHHI. MM 


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M 


rHh« Hearth* Ml-* 

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fOrororOiNMCMMC^NCSClC^OlMMHMMtHMMM 


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Cd-* «|tX «>NM|-iJ.M|^M|T)( 

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t^LOtO"^(N N M OOOOOCO t^O uouofOrON m m OOO 


00 


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t^ t^o lo 










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COl^Mlm 

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t^NO NO 










M M 


rtiM rHlc> H-* c>^Hi<«l-*-l^^rt|^«H<-^lc^-^^NH^> 
M On On t^ I>.nO lo uo ^ rD rO rO N 


a 


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•CiTttrlkNHCMrHte-) 

00 CO t^NO NO 


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lO LO Tt Tt 










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t^ r^NO uo lO ^ -"^ CO ro 






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m|-*«|TJ<-|C-»rHH<H-* rtrftrlh* rHh* rt|M Ml-* M|-* iHkN 
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CO CO CO <N CM 


M O O OnOO 00 00 f^ t^ t— I>.NO MO NO NO 


COH< COH<rt|C<rHhilM|T)lr-lH< Cd^ 

lOiOiO'^'^-^CDfOrOPOCM 


MM 
CN (N) 


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OnOO 00 00 t-^ r^ t^NO nOnO inin\niJ^iriU~i-^'^-rt- 


Ml-* i-^Sn H-* Ml-* ihKm HtM H-* 
rO PD CO C^ CM CM CM 


C^ M 


lHH'CO|T»lH^<rH|t<lM|-*M|-*.-HkNr-(l-*H'*«)|T(«lH|Mrt|C^rt|MH-* >-<|OrH^rth* lH|CqiHhH 


CM 


MM 
CM M 


M|CMM|-* 
H M 


HMH-* C<!|-*r^>MH'*'Hh* rt|C<lrH|C^w|^THh*W|^ „|^„MiH|C^rHh*rHh*' C>5|tJ( HC-» iH^ HCI 

lOVOU-jTt^Tt'^'^'^t-fOfOfOfOcorOrOM W n <ni <n cq h m m m 


MM 
M H 




w 


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MMMMMMMM 


M 


Ml-* 


MM MM 






ccNe^-* 


mN Ml-* Hfi Hf^ rtiM HN r^KN HM rtN 








O W rOM ^nO Lor^'^LOONONONfOG rOior-^ONO O O •^ 

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152 



MILLING AND MILLING CUTTERS 



MILLING HEART-SHAPED CAMS 

One method of producing heart-shaped cams is as follows: 
Lay out the curve of the cam roughly, as in Fig. i. Drill and re- 
move the outside stock, being sure to leave sufficient stock to over- 
come errors in laying out. Put the cam on the nut arbor and tighten 
securely. If the roll of the cam is | radius, select a milling cutter 
having the same radius, as the roll of the cam must come to the lowest : 
point, which it would not be able to do if a cutter of a smaller radius 
than that of the roll were used. It would also make a difference to 
the other points on the curve of the cam, which is not quite so 
apparent at first glance. 




Fig. I. — Method of Laying 
Out Cam 



Fig. 2. — Position of Cam and 

Cutler when Commencing 

to Mill 



Selecting an Index 

The next operation is to place the cam between centers on the 
milling machine, having the cutter in line with the vertical radius 
of the cam, at its lowest point. Next choose an index circle which 
will give a division of the cam such that the rise of each division will 
be in thousandths of an inch, if possible. For this cam take a circle 
which will give 200 divisions. As this will make 100 divisions on 
a side, the rise of each division will be o.oii of an inch. Now raise 
the table to the required hight, starting at the lowest point of the 
cam, and mill across, as in Fig. 2. 



MILLING CAMS 153 

Moving the Table 

For the other cuts lower the table o.oii each time, and revolve 
the cam one division until the highest point of the cam is reached, 
then raise the table o.oii for each division of the cam. 

When the cam comes from the milling machine there will be found 
to be small grooves left between the cuts. These may be easily 
removed by smoothing off with a file without impairing the accuracy 
of the cam. 

Most screw-machine cams can be made in this manner, and thev 
will be found to be more accurate than if laid out and filed to the 
line, and also much easier to make after one has become accustomed 
to the method. 



MILLING CAMS BY GEARING UP THE 
DIVIDING HEAD 

By the method here shown, cams of any rise may be milled with 
the gears regularly furnished with the milling-machine. 

\ 

b 

Angle of E/levation \ ^ 



of Index Head 



.V. 



-Lead for vrbicb Milling Machine is Geared- 



FlG. 3,— Diagram for Angle of Index Head 



With the head set vertically the lead of the cam would be the same 
as the lead for which the machine is geared, while with the head 
horizontal and the milling spindle also, a concentric arc, or rest, would 
be milled on the cam, regardless of how the machine was geared. 
By inclining the head and milling spindle, we can produce any lead 
on the cam less than that for which the machine is geared. 

The method of finding the inclination at which to set the index 
head is shown in Fig. 3, and is simply the solution of a plain right- 
angled triangle, in which the hypothenuse represents the lead of the 
machine, and one of the other sides represents the lead we wish to 
produce on the cam. By dividing the latter by the former we get 
the sine of the angle of inclination. 

Take for illustration a plate cam having |-inch rise in 300 degrees. 
^60 

which is the lead we want on the cam, while the slowest lead for which 
the B & S. machine can be geared is 0.67 

0.15 

—— = 0.234. 



IS4 



MILLING AND MILLING CUTTERS 



Consulting a table of sines, we find 0.224 approximates closely the 
sine of 13 degrees, which is the angle at which to set the head, and 
if the milling spindle is also set at the same angle, the edge of the 
cam will be parallel with the shaft on which it is to run. Fig. 4 
shows a milling-machine set for this job. 

When a cam has several lobes of different leads, we gear the 
machine up for a lead somewhat longer than the longest one called 
for in that cam, and then all the different lobes can be milled with 
the one setting of gears, by simply altering the inclination of head 
and milling spindle for each different lead on the cam. 

If the diameter of the cam and the inclination of the head will 
admit, it is better to mill on the under side of the cam, as that brings 
the mill and the table nearer together and thus increases rigidity, 
besides enabling us to easily see any lines that may be laid out on 
the flat face of the cam. Also the chips do not accumulate on the 
work. 




Fig. 4- — Dividing Head Set for Cam Milling 

The work is fed against the cutter by turning the index crank, 
and on coming back for another cut we turn the handle of the milling- 
machine table. As a result the work will recede from the cutter 
before the cam blank commences to turn, owing to back lash in the 
gears, thus preventing the cutter from dragging over the work while 
running back. 

In this way we use to advantage what is ordinarily considered a 
defect in machine construction. 

The milling -machine, when used as shown in Fig. 4, will be found 
to be more rigid than when the head is set in the vertical position, 
and the cams will work more smoothly on account of the shearing 
action of the cutter. 

One possible objection to the method here advocated is the neces- 
sity of using, in some cases, an end mill of extra length of tooth. In 
practise, an end mill |-inch diameter and with a 3J-inch length of 
tooth is not unusual; but the results in both speed and quality will 
be found entirely satisfactory. 



MILLING SCREW MACHINE CAMS 155 



TABLES OF SETTINGS FOR MILLING SCREW 
MACHINE CAMS 

Computed by the Cincinnati Milling Machine Co. 

On the preceding pages an explanation is given of the methods of 
computing the angle at which to set the dividing head and milling 
head for cutting spiral screw machine cams or other cams of similar 
form to any desired lead. For leads below 0.6 inch the method 
referred to will be of direct service, but where the lead is greater than 
0.6 inch the following tables can be used to great advantage as these 
give at once the settings of dividing head and vertical milling attach- 
ment for leads from 0.6 inch to 6 inches. 

These tables give all the information necessary and it only remains 
for the milling machine operator to select the lead of the desired cam 
from the tables and set up for the corresponding change gears and 
angles. 

In setting the vertical milling attachment read the angle direct 
from the dial. Example: if the angle given in the table is 395 
degrees, set the spindle 39^ degrees from, its vertical position. 




Fig. 5. — ^ Milling Cams 

In setting the dividing head, subtract the angle in the table from 
90 degrees. The difference represents the angle to which the dividing 
head spindle must be raised from the horizontal position. 

Example : The angle given in the table is 39I degrees. 90 degrees — 
39^ degrees equals 50^ degrees. 

Set the dividing head spindle 50I degrees up from the horizontal 
position. This angle is read direct from the dial. The set up is 
shown in Fig. 5. 

The tables may of course be used in connection with the cutting of 
any other similar cams. 



156 



MILLING AND MILLING CUTTERS 





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125 


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72 


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64 


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86 


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.827 


24 


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24 


72 


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24 


86 


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24 


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24 


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.780 


24 


72 


24 


86 


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.830 


24 


64 


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.880 


24 


64 


24 


100 


12 


.781 


24 


72 


24 


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24 


72 


28 


86 


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.881 


24 


64 


28 


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.782 


24 


72 


28 


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.832 


24 


72 


24 


86 


26* 


.882 


24 


64 


24 


100 


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.783 


24 


64 


24 


100 


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.833 


24 


56 


24 


100 


36 


.883 


24 


h 


24 


86 


32* 


.784 


24 


72 


24 


100 


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24 


86 


32 


100 


21 


.884 


28 


86 


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86 


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.835 


24 


72 


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.885 


24 


64 


24 


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.786 


28 


86 


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.836 


24 


72 


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24 


64 


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64 


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24 


72 


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86 


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86 


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56 


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86 


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72 


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64 


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24 


64 


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.791 


24 


64 


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72 


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56 


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86 


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.892 


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72 


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86 


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.843 


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72 


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86 


39 


•893 


28 


86 


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72 


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86 


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24 


86 


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•894 


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72 


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86 


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.84s 


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72 


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.895 


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64 


28 


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31* 
15* 


• 796 


24 


64 


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86 


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.846 


24 


64 


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100 


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.896 


24 


72 


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86 


•797 


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72 


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86 


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.847 


24 


86 


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18- 
195 


.897 


24 


72 


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86 


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64 


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86 


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72 


32 


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86 


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86 


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72 


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72 


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64 


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56 


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86 


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56 


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64 


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24 


72 


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28 


86 


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28 


86 


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86 


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28 


86 


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24 


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24 


64 


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64 


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72 


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86 


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64 


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24 


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86 


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72 


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24 


72 


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56 


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24 


64 


24 


86 


19 


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72 


32 


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13 


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24 


64 


24 


86 


26 


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28 


86 


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56 


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86 


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56 


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24 


72 


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24 


72 


32 


86 


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24 


64 


24 


86 


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24 


72 


28 


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24 


56 


24 


100 


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24 


56 


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24 


72 


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72 


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56 


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24 


56 


24 


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24 


56 


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86 


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72 


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28 


86 


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56 


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86 


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MILLING SCREW MACHINE CAMS 



159 





i 


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24 


86 


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86 


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28 


86 


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16 


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24 


72 


28 


86 


14 


I-I54 


24 


64 


28 


86 


19 


1.254 


24 


64 


32 


86 


26 


1.056 


24 


56 


24 


86 


28 


1.156 


24 


64 


32 


100 


I5i 


1.256 


24 


64 


28 


72 


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24 


86 


40 


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24 


S6 


24 


86 


i4i 


1.258 


28 


86 


40 


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28 


86 


40 


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24 


56 


24 


86 


14 


1.260 


28 


86 


40 


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1.062 


24 


72 


28 


86 


12 


1. 162 


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64 


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32 


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86 


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24 


64 


32 


100 


14 


1.264 


24 


72 


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24 


56 


24 


86 


27 


1. 166 


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72 


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29 


1.266 


28 


86 


40 


100 


13* 


1.068 


24 


64 


28 


86 


29 


1. 168 


24 


56 


24 


86 


12* 


1.268 


24 


72 


40 


TOO 


18 


1.070 


24 


86 


40 


100 


i6| 


1. 170 


24 


56 


24 


86 


12 


1.270 


24 


72 


44 


100 


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28 


72 


32 


100 


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1. 172 


24 


56 


24 


86 


11* 


1.272 


28 


72 


32 


86 


28* 


1.074 


24 


64 


32 


100 


26* 


1. 174 


24 


56 


24 


86 


II 


1.274 


28 


86 


40 


100 


12 


1.076 


24 


64 


32 


86 


39l 


1. 176 


24 


56 


24 


86 


loi 


1.276 


28 


86 


40 


100 


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1.078 


24 


86 


40 


100 


15 


1. 178 


24 


56 


24 


86 


10 1 


1.278 


28 


86 


40 


100 


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24 


86 


40 


100 


I4i 


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24 


64 


32 


100 


io| 


1.280 


28 


86 


40 


100 


10* 


1.082 


28 


86 


44 


100 


41 


1. 182 


24 


64 


32 


100 


10 


1.282 


28 


86 


40 


100 


10 


1.084 


24 


S6 


24 


86 


25 


1. 184 


24 


64 


32 


100 


9i 


1.284 


24 


72 


40 


100 


15* 


1.086 


28 


86 


40 


100 


33i 


1. 186 


24 


86 


44 


100 


IS 


1.286 


40 


64 


24 


100 


31 


1.088 


24 


56 


24 


86 


245 


1. 188 


24 


72 


40 


100 


27 


1.288 


24 


72 


40 


100 


IS, 


1.090 


24 


72 


32 


86 


28- 


1. 190 


24 


64 


28 


86 


^3, 


1.290 


24 


72 


40 


100 


14* 


1.092 


24 


86 


40 


100 


12 


1. 192 


24 


64 


28 


86 


I2i 


1.292 


32 


S6 


24 


100 


19* 


1.094 


24 


86 


40 


100 


III 


1. 194 


24 


64 


28 


86 


12 


1.294 


24 


86 


48 


100 


15 


1.096 


24 


86 


40 


100 


II 


1. 196 


28 


72 


32 


100 


16 


1.296 


24 


72 


40 


100 


13* 


1.098 


28 


72 


32 


100 


28 


1. 198 


24 


72 


32 


86 


IS 


1.298 


24 


64 


32 


86 


21* 


1. 100 


28 


72 


32 


86 


4oi 


1.200 


24 


72 


32 


86 


14* 


1.300 


24 


86 


48 


100 


14 


1. 102 


24 


64 


28 


86 


25§ 


1.202 


24 


64 


28 


86 


10 


1.302 


24 


64 


32 


86 


21 


1. 104 


24 


86 


44 


100 




1.204 


28 


72 


32 


100 


I4f 


1.304 


24 


72 


40 


100 


12 


1. 106 


40 


64 


24 


100 


42I 


1.206 


24 


72 


32 


86 


I3i 


1.306 


24 


72 


40 


100 


II* 


1. 108 


24 


86 


44 


100 


2S2 


1.208 


24 


72 


32 


86 


13 


1.308 


24 


72 


40 


100 


II 


I. no 


24 


72 


32 


86 


26- 


1. 210 


28 


72 


32 


100 


13I 


1.310 


24 


64 


28 


72 


26 


1. 112 


24 


72 


40 


100 


33l 


1. 212 


28 


72 


32 


100 


13 


1. 312 


40 


64 


24 


100 


29, 


1. 114 


24 


64 


32 


86 


37 


1. 214 


24 


86 


48 


100 


2S 


1.314 


28 


86 


44 


100 


23* 


1. 116 


24 


56 


24 


86 


21 


1. 216 


32 


56 


24 


100 


27i 


1.316 


28 


64 


32 


100 


20 


1. 118 


28 


72 


32 


100 


26 


1. 218 


24 


72 


40 


100 


24 


1.318 


24 


86 


48 


100 


10* 


1. 120 


24 


S6 


24 


86 


20i 


1.220 


28 


86 


40 


100 


20i! 


1.320 


24 


86 


48 


100 


10 


1. 122 


24 


86 


44 


100 


24 


1.222 


24 


72 


40 


100 


23* 


1.322 


i8 


72 


32 


86 


24 


1. 124 


24 


56 


24 


86 


20 


1.224 


28 


86 


40 


100 


20 


1.324 


32 


S6 


24 


100 


IS 


1. 126 


24 


86 


44 


100 


23i 


1.226 


24 


72 


48 


100 


40 


1.326 


32 


86 


40 


100 


27 


1. 128 


24 


64 


32 


100 


20 


1.228 


28 


86 


44 


100 


31 


1.328 


28 


64 


32 


100 


18* 


1. 130 


24 


72 


40 


100 


32 


1.230 


28 


64 


32 


100 


28- 


1.330 


H 


56 


24 


100 


14 


1. 132 


24 


64 


28 


86 


22 


1.232 


24 


72 


40 


100 


22- 


1.332 


28 


64 


32 


100 


18 


I-I34 


24 


56 


24 


86 


182 


1.234 


24 


86 


48 


100 


23 


1.334 


24 


64 


32 


86 


17 


1.136 


24 


64 


28 


86 


2I2 


1.236 


24 


72 


40 


100 


22 


1.336 


32 


56 


24 


100 


13 


1.138 


24 


64 


32 


100 


18- 


1.238 


28 


86 


40 


100 


18 


1.338 


32 


56 


24 


100 


12* 


1. 140 


24 


64 


28 


86 


21 


1.240 


24 


72 


40 


100 


2I| 


1.340 


24 


72 


44 


100 


24 


1. 142 


24 


64 


32 


86 


35 


1.242 


28 


86 


40 


100 


17* 


1.342 


28 


64 


32 


100 


16* 


1. 144 


24 


56 


24 


86 


17 


1.244 


24 


72 


40 


100 


21 


1.344 


24 


64 


32 


86 


15^ 


1. 146 


24 


86 


44 


100 


21 


1.246 


32 


72 


40 


100 


4S§ 


1.346 


32 


S6 


24 


100 


II 


1. 148 


24 


64 


32 


xoo 


17 


1.248 


28 


86 


40 


100 


16* 


1.348 


32 


S6 


24 


100 


10* 



i6o 



MILLING AND MILLING CUTTERS 







« 









1 




4) 


S 










(U 


3 








1 


rt 
^ 








a 



.2 


.2 


I 






g 


.2 

'3 


4 


S 




^ 


a 


s 


CO 






^ 


1 


i 


cJd 






^ 


6 


in 




c 


fe 


OJ 


c 






c 


3 


V 


c 









^ 


S 


a 


T} 



>- 


c 


C 





S 


•T3 



1- 


c 


d 





S 


-0 




a 


c 





i 





56 


c 

24 


100 


1 

10 


J 





M 


ci 





be 

< 


i 



44 


64 


1 
24 


100 


•350 


I.4SO 


32 


86 


40 


100 


13 


1.550 


•352 


28 


64 


32 


100 


15 


1.452 


40 


64 


24 


100 


I4§ 


1-552 


24 


72 


48 


100 


•354 


24 


^ 


32 


86 


14 


1-454 


28 


86 


48 


100 


2I2 


1-554 


24 


64 


40 


86 


.356 


24 


64 


32 


86 


13! 


1.456 


24 


72 


40 


86 


20 


1-556 


24 


64 


32 


72 


.358 


28 


64 


32 


100 


14 


1.458 


32 


86 


40 


100 


11^ 


1-558 


24 


72 


44 


86 


.360 


28 


72 


32 


86 


20 


1.460 


24 


44 


32 


86 


44 


1.560 


44 


64 


24 


100 


.362 


24 


64 


32 


86 


12I 


1.462 


40 


64 


24 


100 


13 


1.562 


24 


72 


48 


100 


.364 


24 


64 


32 


86 


12 


1.464 


40 


64 


24 


100 


I2i 


1.564 


24 


72 


44 


86 


.366 


24 


64 


28 


72 


20J 


1.466 


24 


72 


40 


86 


19 


1-566 


32 


86 


44 


IOC 


.368 


28 


72 


32 


86 


19 


1.468 


28 


64 


40 


100 


33 


1-568 


24 


72 


48 


lOO' 


.370 


28 


f 


44 


100 


'^ 


1.470 


40 


64 


24 


100 


Hi 


I-S70 


32 


72 


40 


1 00 


.372 


24 


64 


32 


86 


lof 


1.472 


40 


64 


24 


100 


II 


1-572 


28 


64 


32 


86 


■374 


24 


64 


32 


86 


10 


1.474 


24 


72 


40 


86 


18 


1-574 


32 


86 


44 


100 


.376 


28 


11 


32 


86 


18 


1.476 


28 


72 


40 


TOO 


i8| 


1.576 


24 


72 


48 


100 


.378 


28 


86 


44 


100 


16 


1.478 


24 


72 


40 


86 


i7i 


1-578 


44 


64 


24 


100 


.380 


28 


72 


32 


86 


nh 


i 1.480 


28 


72 


40 


100 


18 


1.580 


28 


64 


32 


86 


.382 


24 


64 


32 


72 


34 


! 1.482 


24 


72 


40 


86 


17 


1-582 


44 


64 


24 


100 


3S4 


28 


86 


44 


100 


15 


1.484 


28 


72 


40 


100 


i7i 


1-584 


■ 40 


56 


24 


100 


386 


40 


64 


24 


100 


22^ 


1.486 


24 


72 


40 


86 


i6i 


1.586. 


28 


64 


32 


86 


388 


28 


64 


32 


86 


31^ 


1.488 


28 


72 


40 


100 


17 


1-588 


32 


86 


44 


100 


390 


28 


86 


44 


100 


14 


1.490 


24 


72 


40 


86 


16 


1.590 


44 


64 


24 


100 


392 


44 


64 


24 


100 


325 


1.492 


28 


72 


40 


100 


i6i 


1.592 


28 


64 


32 


86 


394 


28 


72 


32 


86 


155 


1.494 


24 


72 


40 


86 


ish 


1-594 


44 


64 


24 


100 


396 


28 


86 


44 


100 


13 


1.496 


28 


72 


40 


100 


16 


1.596 


28 


64 


44 


100 


398 


28 


72 


32 


86 


15 


1.498 


32 


64 


•40 


100 


4ii 


1.598 


28 


64 


32 


86 


400 


40 


64 


24 


100 


21 


1.500 


28 


64 


40 


ICO 


31 


1.600 


44 


56 


24 


100 


402 


28 


86 


44 


100 


12 


1.502 


28 


86 


48 


100 


16 


1.602 


24 


64 


32 


72 


404 


28 


72 


32 


86 


14 


1-504 


24 


72 


40 


86 


14 


1.604 


32 


86 


44 


100 


406 


28 


86 


44 


100 


II 


1.506 


28 


72 


40 


100 


14* 


1.606 


24 


64 


32 


72 


408 


24 


64 


28 


72 


IS 


1.508 


24 


72 


48 


100 


I9I 


1.608 


44 


64 


24 


100 


410 


28 


72 


32 


86 


13 


1. 510 


24 


72 


40 


86 


13 


1. 610 


32 


86 


44 


100 


412 


24 


64 


28 


72 


I4i 


I-512 


24 


64 


44 


86 


2^ 


1. 612 


32 


86 


44 


100 


414 


24 


72 


44 


100 


iSi 


I-514 


24 


72 


48 


86 


35i 


T.614 


44 


64 


24 


100 


416 


24 


64 


44 


86 


42i 


1-S16 


24 


72 


40 


86 


12 


1.616 


40 


56 


24 


100 


41S 


28 


72 


32 


86 


iih 


I-518 


32 


86 


44 


100 


22 


1.618 


24 


64 


32 


72 


420 


28 


72 


32 


86 


II 


1-520 


28 


86 


48 


100 


I3i 


1.620 


44 


64 


24 


100 


422 


40 


64 


24 


100 


i8§ 


1.522 


24 


72 


40 


86 


II 


1.622 


44 


64 


24 


100 


424 


28 


64 


32 


86 


29 


1.524 


24 


72 


40 


86 


loj 


1.624 


24 


64 


32 


72 


426 


24 


64 


28 


72 


12 


1.526 


24 


72 


40 


86 


10 


1.626 


24 


72 


44 


86 


428 


28 


86 


48 


100 


24 


1.528 


32 


86 


44 


100 


21 


1.628 


24 


64, 


32 


72 


430 


32 


86 


40 


TOO 


16 


1-530 


28 


72 


40 


100 


lol 


1.630 


24 


64 


32 


72 


432 


24 


72 


44 


100 


I2§ 


1-532 


28 


72 


40 


100 


10 


1.632 


28 


72 


.44 


100 


434 


24 


64 


28 


72 


lol 


1-534 


28 


86 


48 


100 


II 


1.634 


24 


64 


32 


72 


436 


24 


64 


28 


72 


10 1 


1-536 


32 


72 


40 


86 


42 


1.636 


24 


64 


32 


72 


438 


24 


72 


44 


100 


II^I 


1-538 


H 


72 


48 


100 


16 


1.638 


32 


86 


48 


100 


440 


24 


72 


44 


100 


io|l 


1-540 


28 


100 


56 


72 


45 


1.640 


28 


72 


40 


86 


442 


24 


72 


44 


100 


1-542 


24 


72 


48 


100 


15* 


1.642 


24 


64 


32 


72 


444 


32 


86 


40 


100 


14 


1-544 


28 


64 


32 


86 


m 


1.644 


24 


64 


40 


86 


446 


24 


72 


44 


86 


32 


1.546 


24 


72 


48 


100 


15 


1.646 


28 


72 


40 


86 


448 


28 


72 


40 


100 


2lh 


I-S48 


28 


64 


32 


86 


18 


1.648 


40 


56 


24 


100 



MILLING SCREW MACHINE CAMS 



i6i 







V 


5 










1) 


a 










« 


« 








1 


1 


.2 

a 


s 






a 


.2 


.3 








1 


a 


1 


in 






cl 


u 


ij 


d 






fl 


s 


4) 


a 






cl 




1; 


c 











a 














C 














d 







-o 




ili 






Ji 


•r} 


u 


c 






Ji 


—J 




a 







S 


J 




3i 




^ 



1 

19? I 


750 


32 


M 

86 


i 
48 


100 


to 
a 
< 

III 


2 


i 



^ 


i 


bjO 

a 
< 


1. 650 


28 


64 


40 


100 


1.850 


28 


64 


44 


100 


16 


I.-652 


40 


56 


24 


100 


i5i I 


752 


28 


100 


5^ 


86 


16 


1.852 


28 


72 


44 


86 


2I| 


i.6S4 


24 


72 


44 


86 


14 I 


754 


28 


72 


48 


100 


20 


1.854 


44 


56 


24 


100 


io| 


1.656 


28 


72 


44 


100 


14^ I 


7S6 


32 


86 


48 


100 


loi 


1.856 


24 


64 


40 


72 


27 


1.658 


24 


72 


44 


86 


I3i I 


758 


32 


72 


44 


100 


26 


1.858 


24 


64 


44 


86 


I4I 


1.660 


28 


72 


44 


100114 1 I 


760 


28 


72 


48 


100 


19I 


1.860 


32 


72 


44 


100 


18 


1.662 


32 


86 


48 


IOO|2l|| I 


762 


28 


64 


32 


72 


25 


1.862 


24 


64 


44 


86 


14 


1.664 


28 


72 


44 


100 I3I! I 


764 


24 


72 


48 


86 


i8| 


1.864 


28 


64 


44 


100 


144 


1.666 


28 


64 


32 


7231 1 I 


766 


28 


72 


40 


86 


12I 


1.866 


24 


64 


44 


86 


I3I 


1.668 


24 


72 


44 


86 


12 I 


768 


32 


72 


48 


100 


34 


1.868 


28 


64 


44 


100 


14 


1.670 


28 


72 


44 


100 


12 J I 


770 


28 


72 


48 


100 


i8i 


1.870 


24 


64 


44 


86 


13 


1.672 


24 


64 


40 


86 


i6|j I 
II 1 I 


772 


44 


56 


24 


100 


20 


1.872 


28 


64 


44 


100 


I3I 


1.674 


24 


72 


44 


86 


774 


24 


72 


48 


86 


I7i 


1.874 


24 


64 


44 


86 


I2I 


1.676 


24 


72 


44 


86 


I oil I 


776 


28 


72 


40 


86 


II 


1.876 


28 


64 


44 


100 


13 


1.678 


28 


64 


40 


100 


1 6^1 I 


778 


44 


56 


24 


100 


19* 


1.878 


28 


64 


32 


72 


15 


1.680 


28 


72 


44 


100 


II I 


780 


28 


100 


56 


86 


I2| 


1.880 


24 


64 


44 


86 


III 


1.682 


28 


72 


44 


100 


io| I 


782 


32 


64 


40 


100 


27 


1.882 


28 


64 


32 


72 


I4I 


1.684 


32 


86 


48 


100 


iQi! I 


784 


24 


56 


40 


86 


26I 


1.884 


24 


64 


44 


86 


II 


1.686 


28 


64 


40 


100 


154 I 


786 


28 


100 


56 


86 


III 


1. 886 


28 


64 


44 


100 


11? 


1.688 


40 


56 


24 


100 


10 I 


788 


24 


72 


48 


86 


16 


1.888 


28 


72 


44 


86 


i8j 


i.6go 


28 


64 


40 


100 


15 I 


790 


28 


100 


56 


86 


II 


1.890 


24 


64 


44 


86 


10 


1.692 


24 


64 


40 


86 


14 I 


792 


28 


100 


56 


86 


io| 


1.892 


32 


72 


48 


100 


274 


1.694 


32 


72 


44 


100 


30 I 


794 


44 


56 


24 


100 


18 


1.894 


28 


64 


32 


72 


13 


1.696 


24 


64 


40 


86 


13I I 


796 


28 


64 


32 


72 


22| 


1.896 


28 


64 


44 


100 


10 


1.698 


28 


64 


40 


100 


14 I 


798 


24 


•64 


44 


86 


20i 


1.898 


28 


64 


32 


72 


12I 


1.700 


32 


72 


40 


100 


17 I 


800 


32 


72 


44 


100 


23 


1.900 


28 


64 


40 


86 


21 


1.702 


28 


64 


40 


100 


13 1 I 


802 


28 


64 


32 


72 


22 


1.902 


28 


64 


32 


72 


12 


1.704 


28 


64 


40 


72 


45? I 


804 


32 


72 


44 


86 


37l 


1.904 


24 


64 


48 


86 


24I 


1.706 


24 


64 


40 


86 


12 I 


806 


24 


S6 


40 


86 


25 


1.906 


32 


72 


44 


100 


13 


1.708 


28 


64 


40 


100 


I2i I 


808 


28 


72 


48 


100 


14J 


1.908 


28 


64 


32 


72 


II 


1. 710 


28 


72 


40 


86 


19 I 


810 


28 


72 


48 


86 


331 


1. 910 


32 


72 


44 


100 


12 


1. 712 


24 


64 


40 


86 


II I 


812 


24 


72 


48 


86 


13 


.1.912 


28 


64 


32 


72 


10 


1.714 


32 


64 


40 


100 


31 I 


814 


24 


64 


44 


86 


19 


1-914 


28 


64 


32 


72 


10 


1. 716 


28 


72 


40 


86 


i8i I 


816 


24 


72 


48 


86 


I2| 


1. 916 


24 


56 


40 


86 


16 


1. 718 


24 


64 


40 


86 10 I 


818 


28 


72 


44 


86 


24 


1.918 


28 


72 


44 


86 


is4 


1.720 


28 


72 


40 


86 18 I 


820 


24 


64 


44 


86 


m 


1.920 


32 


72 


44 


100 


II 


1.722 


24 


44 


32 


86 


32 I 


822 


44 


56 


24 


100 


IS 


1.922 


28 


72 


44 


86 


IS 


1.724 


28 


100 


56 


86 


19 I 


824 


40 


86 


44 


100 


27 


1.924 


28 


64 


40 


86 


19 


1.726 


24 


56 


40 


86 


30 I 


826 


24 


72 


48 


86 


II 


1.926 


32 


72 


44 


100 


10 


1.728 


32 


72 


40 


100 


I3h I 


828 


24 


56 


40 


86 


23l 

III 


1.928 


28 


64 


44 


86 


30- 


1.730 


28 


72 


40 


86 


17 I 


830 


28 


72 


48 


100 


I-930 


24 


56 


40 


86 


142 


1.732 


32 


72 


40 


100 


13 I 


832 


24 


72 


48 


86 


10 


1-932 


32 


64 


40 


100 


15 


1-734 


28 


72 


40 


86 


162 I 


834 


44 


56 


24 


100 


I3l 


1-934 


24 


56 


40 


86 


14 


1.736 


32 


72 


40 


100 


125 I 


836 


28 


72 


48 


100 


io| 


1-936 


32 


64 


40 


100 


i4§ 


1.738 


32 


f. 


40 


100 


4O2 I 


838 


44 


56 


24 


100 


13 


1.938 


24 


56 


40 


86 


I3l 


1.740 


32 


86 


48 


100 


13 I 


840 


24 


64 


44 


86 


i6| 


1.940 


28 


64 


48 


100 


22I 


1.742 


32 


72 


40 


100 


II- I 


842 


32 


72 


40 


86 


27 


1.942 


24 


56 


40 


86 


13 


1.744 


32 


86 


48 


100 


vA' 


844 


28 


64 


32 


72 


18I 
i6| 


1.944 


32 


56 


40 


86 


43 


1.746 


24 


64 


44 


86 


846 


28 


64 


44 


100 


1-946 


28 


72 


44 


86 


12 


1.748 


32 


72 


40 


100 


■ o-jx 


848 


44 


56 


24 


'- 


III 


1.948 


32 


72 


40 


86 


I9§ 



l62 



MILLING AND MILLING CUTTERS 





S 


c 




4) 

s 



1 


4) 




E 

1 




.2 




a 


XJ 
g 


s 

1 

c 


.1 


Si 

<LI 

E 


J 

CI 


1 


h-1 





0) 







< 


hJ 




S3 




c 





< 


h-1 





a 


c 







c5 

28 


"tn 


-a 
c 





~ 




6 


S 


T3 
C 












to 




& 




1.950 


72 


44 


86 


III 


2.050 


28 


64 


48 


100 


I2i 


2.150 


32 


72 


44 


86 


19 


1-952 


40 


86 


44 


100 


I7l 


2.052 


28 


^ 


44 


86 


23 i 


2.152 


32 


64 


44 


100 


12 


1-954 


24 


64 


48 


86 


21 


2-054 


28 


64 


48 


100 


12 


2-154 


24 


64 


44 


72 


20' 


1.956 


32 


72 


48 


100 


23I 


2.056 


40 


86 


481100 


23 


2.156 


32 


64 


44 


100 


iij 


1.958 


40 


86 


44 


100 


17 


2.058 


24 


64 


48 


86 


loi 


2.158 


24 


56 


40 


72 


25 


1.960 


28 


72 


44 


86 


10 


2.060 


32 


72 


48 


100 


IS 


2.160 


32 


64 


44 


100 


II 


1.962 


48 


56 


24 


100 


i7i 


2.062 


24 


56 


40 


72 


30 


2.162 


40 


86 


48 


100 


14 ■ 


1.964 


24 


64 


40 


72 


19^1 


2.064 


44 


48 


28 100 


36I 


2.164 


32 


64 


40 


86 


21 


1.966 


28 


64 


40 


86 


15 


2.066 


32 


s6 


40 86 


39 


2.166 


32 


64 


48 


100 


25 


1.968 


40 


86 


44 


100 


16 


2.068 


28 


64 


48 


100 


10 


2.168 


32 


56 


40 


100 


18 


1.970 


32 


64 


40 


100 


10 i 


2.070 


32 


72 


48 


100 


14 


2.170 


32 


72 


48 


86 


29 


1.972 


48 


56 


24 


100 


16- 


2.072 


32 


56 


40 


100 


25 


2.172 


28 


64 


44 


86 


14 


1.974 


24 


44 


32 


86 


13- 


2.074 


32 


72 


48 


100 


I3i 


2-174 


32 


S6 


40 


100 


18 


1.976 


28 


64 


44 


86 


28 


2.076 


28 


72 


48 


86 


17 


2.176 


56 


64 


32 


100 


39 


1.978 


24 


44 


32 


86 


13 


2.078 


32 


72 


48 


100 


13 


2.178 


40 


72 


44 


100 


27 


1.980 


28 


64 


48 


100 


192 


2.080 


32 


64 


44 


100 


19 


2.180 


40 


86 


48 


100 


12I 


1.982 


24 


44 


32 


86 


122 


2.082 


32 


72 


48 


100 


I2i 


2.182 


28 


72 


56 


86 


3oi 


1.984 


28 


48 


40 


86 


43 


2.084 


28 


64 


40 


72 


31 


2.184 


24 


56 


44 


72 


33I 


1.986 


24 


44 


32 


86 


12 


2.086 


32 


72 


48 100 


12 


2.186 


32 


72 


44 


86 


16 


1.988 


28 


56 


32 


72 


2bh 


2.088 


28 


100 


S6| 72 


i6h 


2.188 


28 


56 


32 


72 


10 


1.990 


28 


H 


40 


86 


'^ 


2.090 


32 


72 


48 100 


Hi 


2.190 


32 


56 


40 


86 


34i 


1.992 


48 


56 


24 


100 


'4? 


2.092 


28 


72 


48 1 86 


iSi 


2.192 


40 


86 


48 


100 


II 


1.994 


28 


64 


40 


86 


Ill 


2.094 


32 


72 


48,100 


II 


2.194 


28 


64 


40 


72 


25^ 


1.996 


24 


44 


32 


86 


10* 


2.096 


28 


64 


44 86 


20- 


2.196 


40 


86 


48 


100 


10 


1.998 


28 


64 


40 


86 


" 


2.098 


32 


64 


44 100 


17- 


2.198 


44 


86 


48 


100 


26^ 


2.000 


48 


1^. 


24 


100 


13I 


2.100 


28 


44 


32 


86 


27- 


2.200 


24 


S6 


40 


72 


22^ 


2.002 


40 


86 


44 


100 


12 


2.102 


28 


72 


48 


86 


I4i 


2.202 


32 


72 


44 


86 


14: 


2.004 


28 


64 


40 


86 


10 


2.104 


28 


100 


56 


72 


IS 


2.204 


28 


64 


44 


86 


10 


2.006 


^? 


86 


44 


100 


ii| 


2.106 


28 


72 


48 


86 


14 


2.206 


32 


72 


44 


86 


14 


2.oo8 


48 


56 


24 


100 


12I: 


2.108 


40 


44 


24 


100 


IS 


2.208 


32 


56 


40 


100 


15 


2.010 


^0 


72 


40 


86 


13I 


2. no 


28 


64 


44 


86 


I9i 


2.210 


48 


100 


56 


86 


45 


2.012 


48 


S6 


24 


100 


12 


2. 112 


40 


44 


24 


100 


I4i 


2.212 


32 


64 


40 


86 


18 


2.014 


32 


72 


40 


86 


13 


2. 114 


28 


56 


32 


72 


18 


2.214 


24 


64 


44 


72 


IS 


2.016 


40 


86 


44 


100 


10 


2. 116 


28 


64 


44 


86 


19 


2.216 


32 


72 


44 


86 


13 


2.018 


32 


72 


40 


86 


I2i 


2. 118 


28 


100 


S6 


72 


13- 


2.218 


32 


S6 


40 


100 


14 


2.020 


28 


72 


48 


86 


2I| 


2.120 


28 


72 


48 


86 


12- 


2.220 


32 


72 


44 


86 


I2i 


2.022 


^?. 


72 


4? 


86 


12 


2.122 


28 


100 


56 


72 


13 


2.222 


28 


64 


48 


86 


24i 


2.024 


28 


64 


48 


100 


I5l 


2.124 


28 


72 


48 


86 


12 


2.224 


32 


72 


44 


86 


la 


2.026 


48 


56 


24 


100 


10 


2.126 


28 


100 


56 


72 


12J 


2.226 


44 


86 


48 


100 


25 


2.028 


28 


64 


48 


100 


IS 


2.128 


28 


64 


44 


86 


18 


2.228 


32 


72 


44 


86 


Hi 


2.030 


24 


64 


40 


72 


'^ 


2.130 


28 


100 


56 


72 


12 


2.230 


32 


64 


40 


86 


i6i 


2.032 


32 


72 


40 


86 


10^ 


2.132 


24 


64 


44 


72 


2li 


2.232 


32 


72 


44 


86 


II 


2.034 


24 


64 


40 


72 


I2i 


2-134 


28 


100 


56 


72 


Hi 


2-234 


44 


48 


28 


100 


29 


2.036 


32 


72 


40 


86 


10 


2.136 


28 


S6 


32 


72 


16 


2.236 


32 


72 


44 


86 


10 


2.038 


28 


64 


4^ 


100 


14 


2.138 


28 


72 


48 1 86 


10 


2.238 


24 


64 


44 


72 


12 


2.040 


32 


72 


48 


100 


17 


2.140 


24 


56 


40 72 


26 


2.240 


32 


56 


40 


100 


II 


2.042 


28 


64 


48 


100 


13- 


2.142 


28 


100 


56 72 


10 i- 


2.242 


24 


64 


44 


72 


12 


2.044 


40 


44 


24 


100 


20-j 


2.144 


40 


72 


48 100 


36i 


2.244 


32 


56 


40 


100 


II 


2.046 


28 


64 


48 


100 


13 


2.146 


28 


56 


32! 72 


15 


2.246 


24 


64 


44 


72 


Hi 


2.048 


24 


64 


40 


72 


lO^I 


2.148 


44 


86 


48|ioo 


29 


2.248 


32 


56 


40 


100 


loi 



MILLING SCREW MACHINE CAMS 



163 





g 



.2 




^ 

a 











1 

-0 


t 






s 


.2 


"c3 


^ 

a 






^ 


s 


S 


d^ 


to 


'^ 


^ 


S 


1 


^ 


1 


TS 


^ 


6 


<u 

s 


^ 


1) 




c 






a 


(3 


^ 


c 


ii 




c 






c 


ii 




c 




>^ 





s 


c 





< 





(U 


(3 





< 


U 





<U 


■g 





To 

C3 




rt 


a 










i-i 














a 


»-l 


nj 


< 







^ 


T3 

a 









28 


^ 














^ 


t3 


72 




2.250 


24 


64 


44 


72 


II 


2.500 


64 


48 


72 


31 


2.750 


28 


64 


48 


19- 


2.255 


32 


64 


48 


100 


20 


2-505 


24 


S6 


44 


72 


17 


2.755 


44 


40 


32 


100 


385 


2.260 


44 


56 


32 


100 


26 


2.510 


28 


40 


44 


86 


45 i 


2.760 


28 


44 


48 


86 


39 


2.26s 


28 


44 


32 


86 


17 


2.515 


32 


64 


44 


86 


10^ 


2.76s 


48 


64 


28 


56 


424 


2.270 


28 


44 


32 


86 


16^ 


2.520 


44 


48 


28 


100 


II 


2.770 


28 


48 


44 


72 


39 


2.275 


32 


64 


40 


86 


12 


2.525 


48 


56 


32 


100 


23 


2.775 


40 


72 


44 


86 


12* 


2.280 


28 


h 


44 


72 


3ii 


2.530 


24 


S6 


44 


72 


15, 


2.780 


40 


72 


44 


86 


12 


2.285 


44 


86 


48 


100 


2l| 


2.53s 


32 


56 


4° 


86 


I7f 


2.785 


24 


44 


48 


72 


40 


2.290 


24 


44 


4? 


86 


25§ 


2.540 


32 


64 


48 


86 


24f 


2.790 


28 


48 


44 


72 


38* 


2.295 


32 


64 


48 


100 


17 


2.545 


32 


56 


44 


86 


29I 


2.795 


32 


48 


AO 


72 


41 


2.300 


24 


56 


40 


72 


IS 


2.550 


28 


64 


44 


72 


i7l 


2.8oo 


24 


56 


48 


72 


III 


2.305 


24 


5^ 


40 


72 


14^ 


2.555 


32 


56 


40 


86 


16 


2.805 


24 


56 


48 


72 


II 


2.310 


24 


56 


40 


72 


14 


2.560 


32 


64 


48 


86 


23i 


2.810 


44 


56 


24 


64 


17* 


2.3IS 


24 


56 


40 


72 


I3i 


2.565 


28 


40 


32 


86 10 


2.815 


28 


44 


40 


86 


18 


2.320 


28 


44 


32 


86 


Hi 


2.570 


-14 


4^ 


40 


loo 455 


2.820 


40 


5^ 


44 


86 


39* 


2.325 


28 


44 


32 


86 


II 


2-575 


24 


56 


44 


72 


loi 


2.825 


32 


S6 


44 


72 


36 


2.330 


40 


100 


56 


72 


41I 


2.580 


40 


72 


56 


86 


442 


2.830 


48 


64 


28 


56 


41 


2.33s 


28 


64 


48 


86 


17 


2.585 


32 


56 


40 


86 


13 § 


2.835 


28 


48 


40 


72 


29 


2.340 


24 


56 


48 


72 


35 


2.590 


32 


S6 


40 


86 


^-\ 


2.840 


40 


56 


44 


86 


39 


2.345 


24 


56 


40 


72 


10 


2.595 


44 


40 


32 


lOO 


42^- 


2.845 


28 


44 


40 


86 


16 


2.350 


28 


64 


44 


72 


28§ 


2.600 


32 


56 


40 


86 


12 


2.850 


28 


56 


64 


86 


40 


2.355 


44 


86 


48 


100 


16^ 


2.605 


32 


S6 


40 


86 


Hi 


2.855 


28 


44 


48 


86 


36I 


2.360 


32 


64 


48 


100 


io| 


2.610 


32 


64 


40 


72 


20 


2.860 


40 


56 


44 


86 


384 


2.365 


24 


56 


48 


86 


8^ 


2.615 


44 


48 


40 


100 


44* 


2.865 


24 


44 


48 


72 


38 


2.370 


44 


56 


32 


1 00 


19I 


2.620 


28 


64 


44 


72 


III 


2.870 


44 


48 


40 


100 


385 


2.375 


28 


64 


48 


86 


13^ 


2.625 


44 


56 


24 


64 


27 


2.875 


40 


64 


48 


86 


345 


2.380 


32 


100 


56 


72 


17 


2.630 


48 


56 


32 


100 


i6h 


2.880 


48 


100 


56 


72 


39- 


2.38s 


32 


72 


56 


86 


34^ 


2.635 


40 


72 


44 


86 


22 


2.885 


24 


44 


48 


72 


37* 


2.390 


28 


64 


40 


72 


lOi 


2.640 


48 


100 


56 


72 


45 


2.890 


44 


48 


40 


100 


38 


2.395 


40 


72 


44 


1 00 


ii§ 


2.645 


24 


40 


44 


86 


302 


2.895 


32 


56 


44 


72 


34 


2.400 


56 


64 


32 


lOO 


31 


2.650 


40 


56 


44 


86 


435 


2.900 


28 


44 


40 


86 


III 


2.405 


28 


64 


48 


86 


10 


2.655 


S6 


64 


32 


100 


m 


2.90s 


40 


72 


48 


86 


20 ; 


2.410 


32 


100 


56 


72 


14^ 


2.660 


44 


48 


40 


100 


43 i 


2.910 


28 


44 


40 


86 


10 


2.415 


44 


86 


48 


100 


lol 


2.665 


28 


64 


48 


72 


24 


2.915 


28 


40 


44 


86 


355 


2.420 


32 


100 


56 


72 


13I 


2.670 


28 


48 


44 


72 


4ii 


2.920 


28 


48 


44 


72 


35 


2.425 


32 


100 


56 


72 


13 


2.675 


48 


64 


28 


S6 


44* 


2.925 


40 


64 


48 


86 


33 


2.430 


32 


100 


56 


72 


I2i 


2.680 


28 


44 


48 


86 


41 


2.930 


32 


64 


44 


72 


i6| 


2. 435 


32 


72 


48 


86 


II 


2.68s 


48 


100 


S6 


72 


44 


2.935 


48 


64 


28 


S6 


385 


2.440 


32 


72 


48 


86 


10^ 


2.690 


40 


64 


44 


100 


12 


2.940 


40 


64 


48 


100 


II 


2.445 


44 


56 


32 


100 


13 


2.695 


40 


64 


44 


100 


II- 


2.945 


40 


72 


56 


86 


35 


2.450 


24 


64 


48 


72 


II 


2.700 


28 


44 


48 


86 


40- 


2.950 


40 


64 


48 


100 


10 


2.455 


40 


72 


48 


100 


23 


2.70s 


56 


64 


32 


100 


15 


2.955 


48 


64 


28 


S6 


38 


2.460 


28 


64 


48 


72 


32^ 


2.710 


40 


72 


56 


86 


41* 


2.960 


24 


44 


48 


72 


35l 


2.46s 


32 


64 


44 


86 


iSi 


2.71S 


40 


56 


44 


86 


42 


2.965 


32 


64 


44 


72 


14 


2.470 


28 


40 


32 


86 


18^ 


2.720 


48 


64 


28 


S6 


43* 


2.970 


32 


64 


48 


72 


27 


2.475 


32 


64 


40 


72 


27 


2.725 


44 


48 


40 


100 


42 


2.975 


40 


56 


44 


86 


35l 


2.480 


44 


48 


28 


100 


IS 


2.730 


48 


100 


S6 


72 


43 


2.980 


48 


40 


28 


100 


274 


2.485 


28 


72 


56 


86 


II 


2.735 


44 


40 


32 


100 


39 


2.985 


44 


48 


40 


100 


35l 


2.490 


28 


72 


56 


86 


10^ 


2.740 


28 


44 


48 


86 


39* 


2.990 


28 


48 


44 


72 


33 


2.495 


24 


44 40 


86 


10^ 


2.745 


40 


72 


44 


86 


15 


2.99s 


48 


64 


28 


56 


37 



164 



MILLING AND MILLING CUTTERS 



1 





1 


x) 




^ 
c 


T3 

g 


1 


1 


"3 

a 


1 

g 




S 


g 






1 

g 




hJ 







^ 




u 

03 


< 


^ 





c 







< 


1-1 





2 

a 


c 



u 


< 





40 


1n 


a 


6 









tn 


i 


<u 







0) 




48 


-0 
c 

44 




72 




3.000 


100 


56 


64 


31 


3-250 


44 


H 


48 


100 


10 


3-500 


28 


II 


3 005 


40 


64 


48 


86 30I 


3- 


255 


32 


48 


40 


72 


28* 


3-50S 


28 


48 


44 


72 


10* 


3.010 


28 


56 


64 


86 


36 


3- 


260 


32 


56 


44 


72 


21 


3-510 


40 


72 


56 


86 


14 


3-OI5 


48 


64 


28 


56 


36^ 


3- 


265 


48 


100 


56 


r. 


29 


3-515 


28 


40 


44 


86 


II 


3.020 


48 


100 


56 


72 


36 


3- 


270 


40 


56 


44 


86 


26* 


3-520 


24 


44 


48 


72 


14* 


3-025 


40 


100 


56 


72 


13I 


3- 


275 


44 


40 


32 


100 


215 


3-525 


44 


48 


40 


100 


16 


3-030 


40 


64 


44 


72 


37h 


3- 


280 


48 


64 


28 


56 


29 


3-530 


40 


56 


44 


86 


15, 


3.035 


24 


40 


48 


86 


25 


3 


285 


32 


48 


40 


72 


27 


3-535 


24 


44 


4^ 


72 


13* 


3.040 


44 


48 


40 


100 


34 


3 


290 


32 


44 


40 


86 


13* 


3 -540 


48! 100 


56 


72 


18* 


3-045 


32 


64 


48 


72 


24 


3 


295 


24 


^t 


48 


72 


25 


3-545 


40 56 


"^ 


86 


'4i 


3-050 


40 


56 


44 


100 


14^ 


3 


300 


32 


48 


40 


72 


27 


3-550 


24 


44 


4^ 


72 


12* 


3 -OS 5 


56 


44 


28 


86 


42i 


3 


30s 


40 


72 


56 


86 


24 


3-555 


40 


5^ 


48 


100 


19* 


3.060 


28 


44 


48 


86 


303 


3 


310 


44 


48 


40 


100 


25* 


3-560 


40 


56 


44 


86 


13 


3-065 


40 


56 


44 


86 


33 


3 


3*5 


32 


48 


40 


72 


26* 


3.565 


4? 


64 


44 


72 


21 


3-070 


28 


40 


44 


86 


31 


3 


320 


28 


40 


44 


86 


22 


3.570 


48 


100 


56 


72 


^7, 


3-075 


44 


48 


40 


100 


33 


3 


32s 


40 


56 


44 


86 


24* 


3.575 


24 


44 


48 


72 


10* 


3.080 


40 


64 


48 


86 


28 


3 


330 


28 


56 


64 


86 


26* 


3-580 


44 


48 


40 


100 


12* 


3.085 


28 


56 


64 


86 


34 


3 


335 


28 


64 


56 


72 


III 


3-585 


48 


40 


32 


100 


21 


3-090 


48 


64 


28 


56 


34I 


3 


340 


40 


64 


44 


72 


29 


3-590 


40 


64 


48 


72 


3C| 


3-095 


48 


100 


56 


72 


34 


3 


345 


32 


44 


48 


86 


34* 


3-595 


56 


4? 


28 


100 


23* 


3.100 


24 


44 


48 


72 


3ii 


3 


350 


44 


48 


40 


100 


24 


3.600 


44 


48 


40 


100 


II 


3.105 


40 


100 


S6 


64 


27^- 


3 


355 


48 


100 


56 


72 


26 


3-605 


4! 


H 


28 


56 


16 


3.110 


44 


48 


40 


100 


32 


3 


360 


40 


56 


48 


100 


II* 


3.610 


28 


56 


64 


86 


14 


3. "5 


28 


48 


40 


72 


16 


3 


365 


28 


40 


44 


86 


20 


3-615 


32 


44 


40 


72 


26^ 


3.120 


44 


64 


48 


100 


19 


3 


370 


48 


64 


28 


56 


26 


3.620 


48 


40 


32 


100 


19* 


3-125 


32 


56 


44 


72 


26^ 


3 


375 


44 


48 


4? 


100 


23 


3-625 


44 


56 


48 


100 


16 


3.130 


32 


56 


48 


86 


II 


3 


380 


32 


S6 


48 


72 


27* 


3-630 


32 


48 


40 


72 


II* 


3-135 


28 


44 


48 


86 


28 


3 


385 


48 


64 


28 


56 


25* 


3-635 


28 


40 


48 


86 


21* 


3-140 


32 


S6 


48 


86 


10 


3 


390 


48 


40 


32 


100 


'\ 


3-640 


28 


56 


64 


86 


12 


3-145 


48 


64 


28 


S6 


33 


3 


395 


32 


56 


44 


72 


13* 


3.645 


48 


100 


56 


72 


12* 


3.150 


28 


44 


48 


86 


27i 


3 


.400 


4? 


56 


44 


86 


21* 


3-650 


40 


P 


64 


86 


28 


3.155 


28 


64 


56 


72 


22 


3 


-405 


28 


44 


48 


86 


16* 


3-655 


32 


64 


56 


72 


20 


3.160 


44 


48 


40 


IOC 


3oi 


3 


.410 


32 


48 


40 


72 


23, 


3.660 


28 


48 


56 


86 


15* 


3-i6s 


24 


44 


48 


72 


29* 


3 


-415 


28 


40 


"^i 


86 


17* 


3-665 


4^ 


100 


5^ 


72 


II 


3.170 


28 


48 


40 


72 


12 


3 


.420 


32 


40 


48 


86 


40 


3.670 


48 


100 


56 


•72 


10* 


3-175 


32 


48 


40 


72 


31 


3 


-425 


28 


56 


64 


86 


23 


3-675 


48 


64 


28 


56 


II* 


3-180 


40 


56 


44 


86 


29 


3 


-430 


28 


44 


48 


86 


15 


3.680 


32 


56 


48 


72 


15 


3-185 


40 


100 


S6 


64 


24- 


3 


•435 


44 


48 


40 


100 


20* 


3-685 


28 


4^ 


56 


86 


14 


3.190 


28 


S6 


64 


86 


31 


3 


.440 


48 


100 


5^ 


h 


35 


3-690 


56 


48 


24 


64 


32^ 


3-195 


44 


72 


48 


86 


20* 


3 


■445 


28 


44 


48 


86 


14 


3-695 


44 


56 


48 


100 


II 


3.200 


48 


100 


56 


72 


31 


3 


•450 


28 


56 


64 


86 


22 


3.700 


48 


40 


32 


100 


15 


3-205 


28 


40 


44 


86 


26* 


3 


-455 


40 


56 


44 


86 


19 


3-705 


32 


56 


4f 


72 


13 


3-210 


24 


44 


48 


72 


28 


3 


.460 


40 


72 


5f 


86 


17 


3.710 


44 


100 


56 


64 


15* 


3-215 


40 


64 


48 


72 


39* 


3 


-465 


^2 


H 


5^ 


72 


27 


3.715 


28 


48 


5^ 


86 


12 


3.220 


56 


44 


28 


86 


39 


3 


■470 


28 


48 


56 


86 


^^ 


3.720 


^1 


56 


4^ 


72 


12* 


3-225 


24 


44 


48 


72 


27* 


3 


-475 


40 


56 


44 


86 


18 


3.725 


5^ 


44 


28 


86 


26 


3-230 


48 


40 


28 


IOC 


16 


3 


.480 


28 


48 


44 


72 


12* 


3.730 


48 


64 


32 


56 


29* 


3.235 


32 


72 


64 


86 


12 


3 


485 


40 


56 


44 


86 


17* 


3-735 


45 


64 


44 


72 


12 


3.240 


24 


44 


48 


72 


27 


3 


490 


32 


40 


44 


86 


31* 


3.740 


56 


44 


28 


86 


'^J 


3-245 


28 


40 


44 


86 


25 


3 


495 


24 


44 


48 


72 


16 


3.745 


40 


64 


48 


72 


26 



MILLING SCREW MACHINE CAMS 



i6S 





g 


.2 


.a 


^ 






g 


.3 


.J3 


& 






a 


.3 


B 
■M 


te 






g 


'a 


'S 











-0 


-B 


g 






s 


^ 


^ 









^ 


B 


s 


1 






^ 


a 


g 


en 






^ 


a 


i 


c^ 






a 


5 


5 


c 






c 


flj 


a 


c 






ti 


s 


« 


c 




t3 





c 


M 





Ji 


73 





c 


^ 





Ji 


-0 







c 




t-l 


jj 




c3 



M 


^3 

a 


1 


1 


S 





^ 


1 


s 



c 

< 




rt 



tn 


-a 


2 



a 
< 


3-7SO 


32 


44 


48 


86 


^ 


4.000 


28 


40 


48 


72 


31 


4-250 


28 


48 


56 


72 


20i 


3 


755 


40 


64 


44 


72 


102 


4.005 


40 


64 


48 


72 


16 


4-255 


56 


40 


28 


86 


21 


3 


760 


44 


64 


48 


86 


"n 


4.010 


56 


40 


32 


100 


26| 


4.260 


44 


72 


64 


86 


20h 


3 


765 


^S 


64 


56 


72 


142 


4.015 


40 


64 


48 


72 


I5f 


4-265 


56 


44 


28 


^4 


-^°, 


3 


770 


48 


40 


32 


100 


II 


4.020 


40 


72 


H 


86 


13^ 


4.270 


44 


64 


56 


86 


I7i 


3 


775 


48 


100 


56 


64 


26 


4-025 


40 


64 


48 


72 


IS, 


4-275 


32 


44 


56 


86|25i 


3 


780 


40 


5^ 


48 


86 


181 


4.030 


32 


40 


48 


86 


25i 


4.280 


28 


. 40 


48 


72 


23h 


3 


785 


40 


48 


44 


72 


42 


4-035 


44 


64 


56 


72 


4^ 


4-285 


40 


56 


44 


72 


II 


3 


790 


32 


48 


44 


72 


2I§ 


4.040 


48 


64 


32 


56 


191 


4.290 


28 


48 


56 


72 


19 


3 


795 


56 


40 


28 


lod 


143! 


4-045 


56 


4& 


44 


100 


38.! 


4-295 


56 


48 


24 


64 


II 


3 


800 


56 


44 


28 


86 


232 


4-050 


40 


72 


64 


86 iii| 


4.300 


44 


72 


64 


86 


19 


3 


805 


44 


72 


56 


86 


17 


4-055 


40 


48 


44 


86 18 j 


4-305 


44 


56 


48 


86 


II 


3 


810 


56 


40 


32 


86 


43 


4.060 


40 


64 


48 


72 


13 


4-310 


32 


44 


56 


86 


24i 


3 


815 


56 


44 


28 


86 


23 


4.065 


44 


64 


48 


72 


27^' 


4-315 


28 


48 


56 


72 


18 


3 


820 


56 


40 


28 


100 


13 


4.070 


44 


72 


64 


86 


265 


4.320 


44 


64 


48 


72 


19^ 


3 


825 


44 


72 


56 


86 


16 


4-075 


56 


44 


28 


86 


lOi' 


4-325 


44 


72 


64 


86 


18 


3 


830 


40 


64 


56 


72 


38 


4.080 


44 


S6 


48 


86 


2li 


4-330 


28 


56 


.64 


72 


13 


3 


835 


28 


40 


48 


86 


II 


4-085 


56 


48 


24 


64 


21 


4-335 


56 


40 


28 


86 


18 


3 


840 


32 


48 


44 


72 


I9i 


4.090 


40 


64 


48 


72 


11 


4-340 


72 


48 


24 


64 


39i 


3 


845 


28 


44 


48 


72 


25 1 


4-095 


28 


48 


56 


72 


25i 


4-345 


64 


48 


24 


56 


40J 


3 


850 


40 


64 


48 


72 


225, 


4.100 


48 


100 


56 


^ 


I2i 


4-350 


28 


48 


56 


72 


16} 


3 


8S5 


56 


40 


28 


100 


105 


4.105 


44 


72 


64 


86 


25-! 


4-355 


28 


56 


64 


72 


Hi 


3 


860 


56 


40 


28 


100 


10 


4. no 


48 


64 


32 


56 


162' 


4.360 


32 


44 


56 


86 


23 


3 


865 


56 


40 


28 


86 


32 


4-II5 


40 


56 


44 


72 


I9|. 


4-365 


56 


40 


32 


100 


13 


3 


870 


32 


40 


44 


86 


19 


4.120 


48 


64 


32 


56 


16 1 


4-370 


56 


40 


28 


86 


i6i 


3 


875 


32 


48 


44 


72 


18 


4-125 


28 


44 


48 


72 


13-I 


4-375 


32 


44 


S6 


86 


22i 


3 


880 


32 


44 


56 


86 


35 


4.130 


48 


100 


S6 


64 


10- 


4-380 


48 


72 


64 


86 


28 


3 


88s 


44 


72 


56 


86 


I2| 


4-135 


32 


56 


64 


86 


13-' 


4-385 


40 


48 


64 


86 


45 


3 


?90 


40 


64 


48 


72 


21 


4.140 


28 


40 


48 


72 


27i 


4-390 


56 


40 


32 


100 


11^ 


3 


8q5 


40 


48 


44 


86 


24 


4-145 


28 


48 


56 


72 


^4, 


4-395 


44 


64 


56 


86 


II 


3 


900 


56 


44 


28 


72 


38 


4.150 


48 


64 


32 


^^ 


I4i 


4.400 


40 


56 


48 


72 


22I 


3 


905 


28 


4'!- 


48 


72 


23 


4-155 


44 


72 


64 


86 


24 


4-405 


44 


64 


48 


72 


16 


3 


910 


56 


48 


28 


64 


40 


4.160 


56 


40 


32 


86 


37 


4.410 


56 


44 


24 


64 


22| 


3 


91S 


48 


64 


32 


56 


24 


4-165 


44 


64 


56 


86 


2I5 


4-415 


40 


56 


48 


72 


22 


3 


920 


32 


44 


40 


72 


14 


4.170 


44 


64 


48 


72 


245 


4.420 


48 


72 


64 


86 


27 


3 


92s 


40 


56 


48 


86 


10 


4-175 


56 


44 


24 


64 


29 


4-425 


64 


40 


32 


86 


42 


3 


930 


56 


44 


28 


86 


i8i 


4.180 


56 


40 


28 


86 


23§ 


4-430 


28 


48 


56 


72 


12 : 


3 


935 


32 


48 


44 


72 


15 


4-185 


40 


56 


44 


72 


162 


4-435 


48 


64 


56 


72 


40- 


3 


940 


40 


64 


48 


72 


19 


4.190 


64 


48 


32 


72 


45 


4-440 


44 


72 


64 


86 


I2i 


3 


945 


48 


64 


32 


56 


23 


4-195 


28 


40 


48 


72 


26 


4-445 


56 


48 


tl 


100 


30 


3 


950 


48 


72 


56 


86 


24^ 


4.200 


48 


64 


32 


56 


Hi 


4-450 


32 


44 


86 


20 


3 


955 


32 


44 


48 


86 


13 


4-205 


48 


44 


40 100 


i5i 


4-455 


86 


56 


24 


72 


29i 


3 


960 


28 


44 


48 


72 


21 


4.210 


56 


40 


32JIOO 


20 


4.460 


40 


56 


48 


72 


20§ 


3 


965 


56 


48 


24 


64 


25 


4-215 


48 


44 


40! 100 


15 


4-465 


44 


64 


48 


72 


'^1 


3 


970 


32 


44 


48 


86 


12 


4.220 


32 


44 


561 86 


27 


4.470 


44 


48 


56 


86 


?J| 


3 


975 


32 


56 


64 


72 


38- 


4.225 


48 


44 


40 100 


i4i 


4-475 


28 


40 


48 


72 


3 


980 


32 


40 


44 


86 


132 


4.230 


28 


40 


48 


72 


25 


4.480 


40 


44 


48 


86 


28 


3 


985 


40 


64 


48 


72 


17 


4-235 


40 


56 


44 


72 


14 


4.485 


56 


44 


28 


72 


25 


3 


990 


44 


56 


48 


86 


24^ 


4.240 


32 


44 


48 


72 


29 


4.490 


32 


48 


56 


72 


30 


3-9Q5 


40 


64 


48 


72 


i6i 


4-245 


56 


48 


24 


64 


14 


4.495 


32 


44 


48 


72 


22 



i66 



MILLING AND MILLING CUTTERS 





a 


.2 


.2 


& 






S 


.3 


£. 

rt 








S 


^ 


<u 

.2 


^ 






s 


Ti 


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73 


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s 









^ 


■s 


£ 






^. 


S 


i 




in 






^ 


s 


a 


^ 






^ 


1 


g 


^ 






d 


aj 


fe 


c 






c 


<U 


fe 


c 






c 


fc 


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c 




-r) 





C 


^ 





^ 


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^ 


1 





Ji 


■0 





h- 1 


A 





^ 


c3 


S 



S 







C 
< 


J 


g 



2 


-0 


& 


< 


J 


t 






1 


6 


< 


4.500 


56 


44 


32 


64 


45 


4-750 


32 


44 


48 


72 


iii 


5.000 


48 


64 


56 


72 


31 


4-505 


56 


44 


2& 


64 


36 


4-755 


64 


40 


32 


86 


37 


5.005 


56 


44 


28 


64 


26 


4-510 


44 


64 


56 


72 


32i 


4-760 


44 


5^ 


64 


86 


35f 


5.010 


56 


48 


28 


64 


II 


4-515 


48 


64 


44 


56 1 40 


4-765 


64 


4^ 


24 


56 


33§ 


5.015 


40 


48 


44 


72 


10 


4-520 


86 


56 


24 


72128 


4-770 


86 


48 


24 


72 


37 


5.020 


40 


44 


56 


86 


32 


4-525 


40 


48 


56 


86[53h 


4.775 


86 


56 


24 


64 


34 


5.025 


64 


48 


32 


72 


32 


4-530 


56 


72 


.64 


86'38- 


4-780 


40 


64 


56 


72 


lOi 


5.030 


56 


48 


44 


100 


III 


4-535 


40 


44 


S6 


861 40 


4-785 


44 


5^ 


48 


72 


24 


5.035 


44 


56 


48 


72 


16 


4- 540 


64 


48 


32 


72140 


4.790 


44 


56 


64 


86 


35 


5.040 


32 


44 


56 


72 


27 


4-545 


72 


56 


24 


64 19- 


4-795 


86 


S6 


24 


72 


20i 


5.045 


64 


48 


24 


56 


28 


4-550 


48 


72 


64 


86235 


4.800 


64 


44 


32 


86 


272 


5.050 


48 


64 


40 


56 


19^ 


4-555 


56 


44 


28 


7223 


4.805 


44 


40 


48 


86 


38- 


5.055 


^6 


48 


44 


100 


10 


4-560 


48 


64 


56 


86 21 


4.810 


48 


64 


56 


86 


10 


5.060 


86 


64 


28 


72 


14I 


4-565 


28 


40 


48 


72 


12 


4.815 


32 


40 


44 


72 


10 


5.065 


86 


48 


24 


72 


32 


4-570 


32 


44 


48 


V 


I9i 


4.820 


40 


44 


56 


86 


35- 


5.070 


40 


56 


64 


86 


I7§ 


4-575 


32 


44 


56 


86 


15 


4.825 


64 


48 


32 


72 


35-;i 5.075 


40 


44 


56 


86 


31 


4-580 


48 


64 


44 


56 


39 


4-830 


86 


56 


24 


64 


o2, 


5.080 


64 


48 


32 


72 


31 


4-585 


32 


44 


56 


86 


I4i 


4-835 


48 


64 


40 


56 


25i 


5.085 


86 


56 


24 


64 


28 


4-5QO 


48 


64 


56 


86 


20 


4.840 


56 


48 


28 


64 


1821 


5.090 


32 


48 


56 


72 


II 


4-595 


32 


44 


5^ 


86 


14 


4,845 


^l 


56 


64 


72 


17-; 


5-095 


56 


40 


32 


86 


12 


4.600 


40 


56 


48 


72 


15, 


4-850 


56 


44 


28 


72 


1I2 


5.100 


32 


40 


48 


72 


17 


4-605 


32 


44 


56 


86 


13^ 


4-855 


86 


56 


24 


72 


185 


5-105 


40 


44 


64 


86 


41 


4.610 


40 


56 


48 


72 


14^ 


4.860 


44 


48 


56 


86 


35- 


5. no 


56 


72 


64 


86 


28 


4-615 


32 


44 


56 


86 


13 


4-865 


40 


44 


48 


86 


165 


5-II5 


40 


48 


56 


86 


19^ 


4.620 


40 


56 


48 


72 


14 


4-870 


48 


72 


64 


86 


II 


5.120 


44 


40 


48 


86 


33h 


4-625 


44 


S6 


48 


72 


28 


4.875 


40 


56 


64 


86 


23* 


5-125 


56 


44 


28 


64 


23 


4-630 


86 


56 


24 


64 


36§ 


4.880 


86 


44 


24 


72 


41* 


5-130 


64 


40 


32 


86 


3oh 


4-635 


40 


44 


48 


86 


24 


4.885 


48 


H 


44 


56 


34 


5-135 


40 


56 


64 


86 


15 


4.640 


40 


56 


48' 


72 


13 


4.890 


44 


48 


56 


86 


35 


5.140 


40 


44 


48 


72 


32 


4-645 


48 


64 


56 


86 


18 


4.895 


32 


56 


64 


72 


15* 


5-145 


40 


48 


56 


86 


i8§ 


4.650 


32 


40 


44 


72 


18 


4.900 


72 


44 


24 


64 


37 


5-150 


48 


64 


56 


72 


28 


4-655 


56 


44 


32 


64 


43 


4.905 


64 


44 


32 


86 


25 


5-155 


86 


40 


24 


72 


44 


4.660 


64 


40 


32 


86 


38§ 


4.910 


86 


56 


24 


64 


3ii 


5.160 


40 


48 


56 


86 


18 


4-665 


40 


44 


56 


86 


38 


4.915 


72 


48 


28 


64 


4i§ 


5-165 


44 


64 


56 


72 


IS 


4-670 


64 


48 


32 


72 


38 


4.920 


48 


64 


56 


72 


32i 


5-170 


72 


44 


24 


56 


42i 


4-675 


48 


64 


44 


56 


37* 


4.925 


56 


40 


32 


86 


19 


5-175 


32 


40 


48 


72 


14 


4.680 


64 


48 


24 


56 


35 


4.930 


56 


48 


28 


64 


15 


5-180 


56 


72 


64 


86 


26h 


4.685 


56 


44 


24 


64 


II 


4.935 


56 


72 


64 


86 


3ii 


5-185 


56 


40 


48 


100 


39 


4.690 


32 


44 


56 


72 


34 


4.940 


32 


56 


64 


72 


I3i 


5.190 


40 


56 


64 


86 


12 
29 


4-695 


40 


64 


56 


72 


15 


4.945 


86 


56 


24 


72 


15 


5.195 


44 


48 


56 


86 


4.700 


44 


56 


64 


86 


36i 


4.950 


32 


56 


64 


72 


13 


5.200 


64 


48 


24 


56 


24 


4-705 


48 


72 


64 


86 


m 


4.955 


S6 


40 


28 


64 


36 


5.205 


64 


32 


28 


72 


48 


4.710 


32 


56 


64 


72 


22 


4.960 


32 


56 


64 


72 


I2i 


5.210 


44 


56 


64 


86 


27 


4-71S 


56 


48 


28 


64 


22i 


4.965 


64 


40 


32 


86 


33i 


5.215 


72 


48 


24 


64 


22 


4.720 


56 


44 


28 


72 


I7i 


4.970 


64 


48 


32 


72 


33 


5.220 


48 


64 


56 


72 


26§ 


4-725 


56 


48 


44 


100 


23 


4.975 


44 


64 


56 


72 


21- 


5.225 


48 


56 


64 


86 


35 


4-730 


44 


56 


64 


86 


36 


4.980 


86 


48 


24 


72 


33 2 


5.230 


44 


64 


56 


72 


12 


4-735 


44 


48 


56 


86 


37l 


4.985 


44 


56 


64 


86 


31- 


5-235 


40 


56 


64 


86 


10 


4.740 


72 


56 


24 


64 


10^ 


4.990 


72 


48 


24 


64 


27? 


5-240 


86 


56 


24 


64 


24i 


4-745 


56 


44 


28 


72 


i6§ 


4.995 


32 


44 


56 


72 


28 


5-245 


32 


44 


56 


72 


22 



MILLING SCREW MACHINE CAMS 



167 





s 


.3 


.2 


^ 






a 


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iJ 
.d 


& 






s 


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& 






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C 








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u 




k. 

























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IH 






^ 


S 


I 


d^ 






^ 


1 


ii 


c^ 






^ 


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m 






c 


s 


S 


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c 


S 




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a 


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c 









c 


a 





Ji 


T3 



l-l 


G 


1 





Ji 


'V 





a 


c 





Ji 


,-i 


2 




tr2 


1 





< 


J 





M 


•r) 


S 



a 
< 




1 


i 


a 





< 


.S-2SO. 


56 


40 


28 


64 


31 


5-Soo 


64 


32 


28 


72 


45 


S-750 


64 


4? 


32 


72 


14 


5 255 


44 


56 


64 


86 


26 


5 


505 


56 


72 


64 


86 


18 


5 


755 


86 


48 


24 


72 


15* 


5.260 


64 


48 


24 


56 


23 


5 


510 


72 


56 


32 


64 


31 


^ 


760 


86 


64 


40 


72 


39* 


5.265 


48 


64 


56 


72 


25^ 


5 


SIS 


44 


48 


56 


86 


22i 


5 


765 


44 


48 


56 


86 


15 


5.270 


44 


48 


56 


86 


28 


5 


520 


64 


40 


32 


86 


22 


5 


• 770 


64 


44 


28 


56 


37* 


5-275 


40 


44 


56 


86 


27 


5 


52s 


86 


44 


24 


72 


32 


5 


-775 


48 


64 


44 


56 


II 
12 


5.280 


64 


48 


32 


72 


27 


5 


530 


72 


48 


32 


64 


42* 


5 


780 


40 


44 


56 


86 


5-285 


64 


40 


32 


72 


42 


5 


535 


56 


72 


64 


86 


17 


5 


.785 


64 


48 


32 


72 


12 


5.290 


56 


44 


48 


100 


30 


5 


540 


64 


40 


32 


86 


21^ 


5 


■790 


64 


4? 


32 


86 


13* 


5-295 


44 


48 


56 


86 


27* 


5 


545 


40 


44 


56 


86 


20- 


5 


795 


86 


48 


24 


72 


14 


5-300 


40 


44 


48 


72 29 


5 


550 


56 


72 


64 


86 


16- 


5 


800 


64 


44 


24 


56 


21* 
35* 


5-305 


64 


40 


32 


8627 


5 


555 


48 


64 


44 


56 


19- 


5 


80s 


44 


48 


56 


72 


5-3IO 


56 


44 


28 


6417- 


5 


560 


48 


44 


56 


86 


38I 


5 


810 


86 


48 


28 


72 


33h 


5-315 


56 


40 


28 


7212- 


5 


565 


64 


40 


32 


72 


38* 


5 


815 


86 


44 


24 


64 


37* 


5-320 


44 


56 


64 


86;24§ 


5 


570 


86 


40 


24 


72 


39 


5 


820 


64 


44 


24 


56 


21 


5-325 


56 


40 


28 


72,12 


5 


575 


86 


48 


24 


72 


21 


S 


82s 


64 


40 


32 


72 


35, 


5-330 


64 


44 


32 


86|io 


5 


580 


40 


44 


56 


86 


19* 


5 


830 


86 


48 


24 


72 


12* 


5-335 


6d 


48 


24 


56 21 


5 


58s 


86 


44 


24 


72 


31 


5 


83s 


64 


4? 


32 


86 


II* 


5340 


86 


56 


24 


64*22 


5 


590 


40 


48 


64 


72 


41 


5 


840 


44 


48 


S6 


72 


35 


5-345 


86 


^^ 


24 


72l26i 


5 


595 


56 


40 


28 


64 


24 


5 


845 


64 


40 


32 


86 


II 


5-350 


72 


48 


24 


6418 

72|32^ 


5 


600 


86 


56 


24 


64 


I3§ 


5 


850 


86 


56 


32 


72 


31 


5-355 


40 


56 


64 


5 


605 


48 


64 


44 


56 


18 


5 


8SS 


48 


44 


56 


86 


34 ; 


5-360 


64 


44 


32 


72 34 




610 


40 


44 


56 


72 


37* 


5 


860 


64 


40 


32 


72 


34- 


5-365 


44 


48 


56 


86126 


5 


615 


86 


44 


24 


64 


40 


5 


865 


64 


40 


28 


72 


19^ 


5-370 


64 


48 


24 


56 20 


5 


620 


64 


48 


32 


72 


18* 


5 


870 


72 


48 


32 


64 


38* 


5-375 


86 


44 


28 


72145 


5 


625 


86 


56 


32 


72 


345 


5 


875 


56 


40 


44 


100 


17* 


5-380 


32 


44 


56 


72'i8 


5 


630 


86 


48 


24 


72 192 


5 


880 


86 


56 


32 


72 


30* 


S.385 


56 


72 


64 


86i2i| 


5 


63s 


48 


64 


44 


56 17 


5 


885 


72 


44 


28 


56 


44 


5-390 


86 


48 


24 


72l25f; 


5 


640 


56 


72 


64 


8613 


5 


890 


44 


56 


64 


72 


32* 


5-395 


32 


44 


5^ 


721I7I 


5 


645 


44 


40 


56 


8638 
5616I 


5 


895 


44 


40 


48 


72 


36* 


5-400 


I^ 


32 


28 


72!37§ 


5 


650 


48 


64 


44 


5 


900 


56 


64 


40 


48 


36 


5-405 


64 


44 


28 


^^42 


5 


655 


64 


44 


32 


72 29 


5 


90s 


40 


44 


48 


72 


13 


5.410 


44 


48 


56 


86:25 


5 


660 


48 


64 


56 


72 14 


5 


910 


72 


48 


32 


64 


38 


5-415 


86 


64 


40 


r|44 


5 


665 


48 


64 


44 


56 16 


5 


915 


40 


4^ 


64 


72 


37 


5.420 


72 


48 


24 


64i5§ 


5 


670 


56 


40 


44 


100 23 


5 


920 


40 


48 


56 


72 


24 


5-425 


48 


64 


44 


56I23 


5 


675 


56 


32 


28 


7233* 


5 


92s 


86 


64 


32 


56 


39* 


5-430 


86 


64 


32 


56,45, 


5 


680 


86 


48 


24 


7218 


5 


930 


86 


44 


24 


64 


36 


5-435 


64 


48 


32 


72l23§ 


5 


68s 


44 


56 


64 


86i3§ 
8645^ 


5 


935 


72 


44 


28 


64 


34 


5-440 


^i 


1^ 


64 


86:2ii 


5 


690 


48 


44 


64 


5 


940 


86 


56 


32 


72 


29 


5-445 


48 


64 


44 


561221 


5 


695 


48 


64 


56 


72 


12* 


5 


945 


44 


40 


48 


86 


14 


S-450 


64 


4f 


24 


56:17* 


5 


700 


56 


72 


64 


86 


10 


5 


950 


72 


48 


32 


64 


37 


5-455 


64 


48 


32 


72 23 


5 


705 


40 


44 


56 


86 


15* 


5 


955 


44 


56 


6^ 


72 


31 


5.460 


64 


40 


32 


86 23- 


5 


710 


64 


48 


32 


72 


IS* 


5 


960 


40 


44 


48 


72 


10 


5-465 


44 


^t 


64 


7238^ 


5 


71s 


40 


48 


6a 


72 


39* 


5 


96s 


40 


48 


56 


72 


23 


5-470 


72 


48 


24 


6413. 


5 


720 


4° 


44 


56 


72 


36 


5 


970 


44 


40 


48 


72 


35* 


5-475 


64 


48 


32 


72 225 


5 


725 


86 


44 


24 


72 


28* 


5 


975 


56 


44 


48 


100 


12 


5-480 


48 


56 


64 


7244 


5 


730 


48 


64 


44 


56 


13* 


5 


980 


44 


48 


56 


72 


33 


5-485 


72 


48 


32 


6443 


5 


735 


48 


64 


56 


72 


10* 


5 


985 


40 


56 


64 


72 


19* 


5 -490 


86 


44 


24 


6441I 


5 


740 


44 


56 


64 


86 


II 


"5 


990 


72 


48 


32 


64 


37, 


S-495 


44 


48 


56 


86 23 


5-745 


72 


48 


32 


64 


40 


5-995 


44 


48 


64 


86 


28* 



i68 



MILLING AND MILLING CUTTERS 



PLAIN AND DIFFERENTIAL INDEXING ON BROWN & 
SHARPE MILLING MACHINES 

The general arrangement of the universal dividing head is illus- 
trated in Figs. 1,2, and 3. As indicated by the diagrammatic sketch 
Fig. 2, the worm wheel A is secured to the main spindle of the spiral 
head and rotated by means of the worm shaft and single-threaded 
worm B. The index plate (having rows of equally spaced holes) 
remains stationary during the dividing operation, and is fitted with 
adjustable sector arms which obviate the necessity of counting the 
number of holes tlirough which the index crank requires to be moved 
each time a division is made on the surface of the work. The stan- 




FiG. I. — BrowTi & Sharpe Dividing Head Arranged for 
Differential Indexing 

dard ratio between the worm B and the worm wheel A is i : 40; and 
to find the movement of the index crank for any required division, 
the following formula is employed: The movement of the index 

crank = ^ where N is the number of equal divisions required. 
N 
Example: Let it be required to divide the circumference of a piece 
of work into 48 equal parts. 

The movement of the index crank for each division = ^ = ^ revohi- 
^ ^ 48 6 

lions. ^ 

An index plate having a row of 18 holes would be chosen, and the 
sector arms set to limit the movement of the index crank to 15 spaces 
5 ^ 15. 



for 



18 



General Principle of Differential Indexing 

The number of equal divisions which may be obtained by simple 
indexing (with the index plates usually provided by milling-machine 
makers) is strictly limited, and does not meet all the requirements 
called for in practice. 

Differential indexing provides the most convenient way of over- 
coming this difSculty, this method being simpler than compound 



PLAIN AND DIFFERENTIAL INDEXING 



169 



indexing. In the differential system the dividing operation is per- 
formed as in simple indexing, the only difference being that the index 
plate instead of remaining stationary during the process of indexing, 
is made to move relatively to the index crank, being connected to the 
main spindle of the spiral head by a set of change gears, which may 
be arranged to give either a positive or negative movement to the 




Fig. 2 



Worm Wheel, 
40 Teeth 
Single Thread 
Worm 

Main Spindle 




Index Plate 



Index Crank ' 



Fig. 3 

index plate; whichever is found necessary to determine the actual 
motion which must be given to the index crank in order to satisfy the 
formula given above for simple indexing: Actual movement of the 

index crank = — - • 
N 
The two views in Fig. i and the diagram. Fig. 3, will serve to give 
an idea of the arrangement of the gearing, which is adopted in dif- 
ferential indexing. 



I70 MILLING AND MILLING CUTTERS 

For any movement of the index crank the motion is transmitted to 
the index plate (which is free to rotate on the worm shaft) as follows: 
The index crank drives through the worm shaft and worm B to the 
worm wheel /I, which in turn transmits the motion through the change 
gears, spiral gears and equal gears, the last of which is connected 
directly to the index plate. The last pair of gears being equal and 
driven through equal spiral gears, whatever number of revolutions 
are given to the gear £, the index plate will make the same number. 
It is therefore convenient to consider the revolutions of the gear E, 
as the revolutions of the index plate in all calculations. 

To illustrate the influence of the gearing on the index plate and 
indexing operation, consider the following example: Required to 
index for 107 divisions: 

If we use the plate having 20 holes and move 8 holes per division, 
as in simple indexing for 100 divisions, 100 moves will of course be 
required to rotate the worm 40 turns, which in turn rotates the 
spindle once. If now we make 107 moves with the index plate fixed 

8 
as in simple indexing, we will obtain 107 X — = 42.8 revolutions of 

20 
the worm, which is 2.8 in excess of what is required. Therefore the 
index plate must be geared so that it will move back 2.8 turns while 
the spindle is revolving once; that is, the ratio of the gearing must be 
2.8 to I. 









2^ 

I 


2 


x^ 

I 






2.8 

2 


X 


20 

= 

20 


= 56 
40 






^x3f 
I 32 


= 64 

32 



Then— = ^ X —and the gears will be 64 and 56 for the spindle 
I 40 32 
and first gear on stud, and 40 and 32 for the worm and second gear on 
stud, as shown in Fig. i. As compound gears are used, but' one idler is 
required to cause the index plate to move in a direction opposite to that 
of the crank. For this purpose an idler having 24 teeth is employed. 

Formula for Finding the Gear Ratio 

A simple formula for the determination of the gear ratio necessary 
to rotate the index plate as required for any given number of teeth 
is derived as follows: 

Let N equal the number of divisions required to be indexed. 

Let n equal some number either greater or smaller than A'', which 
can be obtained directly by simple indexing. 

Let ^ equal the index setting; that is the setting of the sector 
n 
arms for each movement of the index crank; 

Then n — N X— equals the gear ratio. 
n 



PLAIN AND DIFFERENTIAL INDEXING 171 

If the number chosen for n is greater than the number of divisions 
required (iV) the index plate must be geared to have a positive motion, 
that is to rotate in the same direction as the index crank. If the 
number n is less than N the index plate is geared to have a negative 
motion, that is, to rotate in opposite direction to the crank. 

Application of the Formula 

Suppose we wish to obtain 63 divisions: choose any number for 
n which may be obtained by simple indexing, say 60, then 

{n - iV) = (60 - 63) = - 3 

This number (— 3) when multiplied by the value of the index setting 

will give the gear ratio. The index setting equals — , equals — , then 

n 60 

{n - N)^= - 3 X^ = -— or ^ as the gear ratio. 

n 60 30 I 

We can therefore use gears of 48 and 24 teeth, the 48 gear being the 
driver and the 24 gear the follower; that is, the 48 gear being on 
the spindle and the 24 gear on the worm. As n is smaller than N 
the idlers are arranged to give a negative movement to the index plate. 

The index setting is found above as — which equals i5 or - • We 

n 60 3 

can thus use the 39 hole circle in the index plate and set the sector 

for 26 holes, this giving the setting as — or - ; that is, we set the sec- 

39 3 
tor and index pin exactly the same as for simple indexing of 60 
divisions. 

The tables on the following pages give the dividing head gears for 
indexing all numbers up to 730. 



172 



MILLING AND MILLING CUTTERS 



1 


1 


"o 


1 


No. I Hole 


-a 
a 

C/2 


Idlers 


•> 

2 


d 


Si 


ui 

S 
^-. 


4J 


rS 


fe 


u 


Hx 


fl 


0^ 


3 


c 


w 


ffi 


S 

3 


1 


:i 




l-i 


^1 


11 





d 


6 


^ 


a 


^ 





b 


C/3 





^ 


Z 


2 


Any 


20 














3 


39 


13H 














4 


Any 


10 














5 


Any 


8 














6 


39 


6ff 














7 


49 


5lf 














8 


Any 


5 














9 


27 


4-lf 














10 


Any 


4 














II 


33 


3II 














12 


39 














13 


39 


3^ 














14 


49 


2ff 














15 


39 


2ff 














16 


20 


2it 














17 


17 


2tV 














18 


27 


'Y 














19 


19 


2tV 














20 


Any 


2 














21 


21 


iff 














22 


33 
















23 


23 


ill 














24 


39 


I2I 














25 


20 














26 


39 


1-9 














27 


27 


l-y 














28 


49 


iii 














29 


29 


I^¥ 














30 


39 


I^f 














31 


31 


I^ 














32 


20 


I^ 














33 


33 


1,\ 














34 


17 


itV 














35 


49 


itV 














36 


27 


lir 














37 


37 


• I3V 














38 


19 


^¥ 














39 


39 


I3V 














40 


Any 


I 














41 


41 


It 














42 


21 


M 















PLAIN AND DIFFERENTIAL INDEXING 173 



s 








No. I Hole 




Idlers 


;| 










V 










> 




"o 


s 


g 


?3 


^ 






Q 
1 











0^ 




-0 


'5, 
00 

§ 




<0 


1 
3 


X 


11 


s 


12 c^ 


8§ 


2 


d 


6 


:^ 


^ 


2 





&H 


cJ^° 





:z; 


^ 


43 


43 


40 














44 


33 


ft 














45 


27 


It 














46 


23 


ft 














47 


47 


ij 














48 


18 


If 














49 


49 


¥9 














50 


20 


M 














51 


17 


T7 


24 






48 


24 


44 


52 


39 


§¥ 














53 


49 


If 


56 


40 


24 


72 






54 


27 


n 














55 


33 


11 














56 


49 


If 














57 


21 


if 


56 






40 


24 


44 


58 


29 


I9 














59 


39 


If 


48 






32 


44 




60 


39 


2 6 
^9 














61 


39 


If 


48 






32 


24 


44 


62 


31 


M 














63 


39 


^6. 


24 






48 


24 


44 


64 


16 


T§ 














65 


39 


11 














66 


33 


ft 














67 


21 




28 






48 


44 




68 


17 


T7 














69 


20 


i^ 


40 






56 


24 


44 


70 


49 


If 














71 


18 


it 


72 






40 


24 




72 


27 


if 














73 


21 


i! 


28 






48 


24 


44 


74 


37 


If 














75 


15 


rJ 














76 


19 


T9 














77 


20 


20 


32 






48 


44 




78 


39 


ft 














79 


20 


it 


48 






24 


44 




80 


20 


it 














81 


20 


2^ 


48 






24 


24 


44 


82 


41 


If 














83 


20 


^0 


32 






48 


24 


44 



174 



MILLING AND MILLING CUTTERS 



1 








No. I Hole 




Idlers 


'> 




•0 ■ 


s 


g 


t. 


T3 






Q 


i 


3 


^0 






in 


-% 





1 


u 


!:e 


§ 


^73 


3 





X 


W 


g 


X 


. G 


>- 


•" 3 


C 


>- 


" 


N 


3 


-o 


1—1 




UiO 


u '^ 


S 


6 


6 


^ 


c 


12; 





S 







^ 


^ 


84 


21 


i^ 














85 


17 


8 














86 


43 


^3 














87 


15 


tV 


40 






24 


24 


44 


88 


33 


if 














89 


18 


t\ 


72 






32 


44 




90 


27 


1} 














91 


39 


U 


24 






48 


24 


44 


92 


23 


M 














93 


18 


tV 


24 






32 


24 


44 


94 


47 


¥ 














95 


19 


tV 














96 


21 


^\ 


28 






32 


24 


44 


97 


20 


^^^ 


40 






48 


44 




98 


49 


II 














99 


20 


2V 


56 


28 


40 


32 






TOO 


20 


A 














lOI 


20 


/o 


72 


24 


40 


'48 




24 


102 


20 


#0 


40 






32 


24 


44 


103 


20 


^ 


40 






48 


24 


44 


104 


39 


¥ 














105 


21 
















106 


43 


if 


86 


24 


24 


48 






107 


20 


A 


40 


56 


32 


64 




24 


108 


27 


^f 














109 


16 


fl 


32 






28 


24 


44 


IIO 


33 
















III 


39 


is. 


24 






72 


32 




112 


39 


II 


24 






64 


44 




113 


39 


"H 


24 






56 


44 




114 


39 


if 


24 






48 


44 




115 


23 


A 














116 


29 


'4 














117 


39 


If 


24 






24 


56 




118 


39 


13 

•39 


48 






32 


44 




119 


39 


if 


72 






24 


44 




120 


39 


if 














121 


39 


¥¥ 


72 






24 


24 


44 


122 


39 


tI 


48 






32 


24 


44 


123 


39 


if 


24 






24 


24 


44 


124 


31 


M 















PLAIN AND DIFFERENTIAL INDEXING 175 




!2 








No. I Hole 




Idlers 






"o 


g 


c 


u 


-3 






Q 


4) 


i 


g 





6 


c 






•0 


a 


p 


?= 


b 


^^ 


'5. 

C/3 




■% 


S 


^ 


t-. 


c 



C-H 


3 


§ 


W 


X 


"s 


S 


°-g 


i-t 


^B 


§C 


tH 


" 


N 


3 


'^ 


^'~' 


6 


.b^ 


° 





6 


6 


^ 


C 


z 





E 


C/2 





^ 


:2; 


125 


39 


fl 


24 






40 


24 


44 


126 


39 


il 


24 






48 


24 


44 


127 


39 


M 


24 






56 


24 


44 


128 


16 


A 














129 


39 


ii 


24 






72 


24 


44 


130 


39 


-y- 














131 


20 


# 


40 






28 


44 




132 


33 


V 














^33 


21 


A 


24 






48 


44 




134 


21 


.^r 


28 






48 


44 




13s 


27 


^ 














136 


17 


tV 














137 


21 


/t 


28 






24 


56 




138 


21 


A 


56 






32 


44 




139 


21 


2*^1 


56 


32 


48 


24 






140 


49 


-it 














141 


18 


T% 


48 






40 


44 




142 


21 


A 


56 






32 


24 


44 


143 


21 


A 


28 






24 


24 


• 44 


144 


18 


T§ 














145 


29 


.> 














146 


21 


^J 


28 






48 


24 


44 


147 


21 


21 


24 






48 


24 


' 44 


148 


37 


^.^ 














149 


21 


2^1 


28 






72 


24 


44 


150 


15 


^^ 














151 


20 


2'0 


32 






72 


44 




152 


19 


A 














153 


20 


2% 


32 






56 


44 




154 


20 


* 


32 






48 


44 




155 


3i 


A 














156 


39 


i^ 














157. 


20 


io- 


32 






24 


56 




158 


20 


h 


48 • 






24 


44 




159 


20 


¥ 


64 


32 


56 


28 






160 


20 


^v 














161 


20 


# 


64 


32 


56 


28 




24 


162 


20 


^^ 


48 






24 


24 


44 


163 


20 


5 

20 


32 






24 


24 


44 


164 


41 


H 














165 


33 


33 















176 



MILLING AND MILLING CUTTERS 



•s 








No. I 


Hole 




Idlers 


•> 




"o 


g 


c 


b 








5 





CJ 


s 





S 


c 






-^ 




p 


^ 


1 


^-^ 








1 


u 









3 
a 


c 



X 




p 


Ci-I 




u 


^ ° 


w 


6 


6 


J^ 


° 


^ 





E 


c^ 





Z 


^ 


166 


20 


2^0 


32 






48 


24 


44 


167 


20 


/o 


32 






56 


24 


44 


168 


21 


¥ 














169 


20 


/o 


32 






72 


24 


44 


170 


17 


17 














171 


21 


^1 


56 






40 


24 


44 


172 


43 


V 














173 


18 


1% 


72 


56 


32 


64 






174 


18 


T% 


24 






32 


56 




175 


18 


t\ 


72 


40 


32 


64 






176 


18 


t\ 


72 


24 


24 


64 






177 


18 


1%- 


72 






48 


24 




178 


18 


T% 


72 






32 


44 




179 


18 


t\ 


72 


24 


48 


32 






180 


18 


t\ 














181 


18 


A 


72 


24 


48 


32 




24 


182 


18 


A 


72 






32 


24 


44 


183 


18 


A 


48 






32 


24 


44 


184 


23 


iV 














185 


37 


A 














186 


18 


t\ 


48 






64 


24 


44 


187, 


18 


t\ 


72 


48 


24 


56 




24 


188* 


47 


i?- 














189 


18 


A 


32 






64 


24 


44 


190 


19 


t\ 














191 


20 


2% 


40 






72 


24 




192 


20 


.% 


40 






64 


44 




193 


20 


/o 


40 






56 


44 




194 


20 


¥ 


40 






48 


44 




195 


39 


A 














196 


49 


H 














197 


20 


/o 


40 






24 


56 




198 


20 


/o 


56 


28. 


40 


32 






199 


20 


.% 


100 


40 


64 


32 






200 


20 


2% 














201 


20 


/o 


72 


24 


40 


24 




24 


202 


20 


* 


72 


24 


• 40 


48 




24 


203 


20 


Y% 


40 






24 


24 


44 


204 


20 


♦ 


40 






32 


24 


44 


205 


41 


^h 














206 


20 


2% 


40 






48 


24 


44 





















PLAIN AND DIFFERENTIAL INDEXING 177 



§ 








No. ] 


Hole 




Idlers 


*tn 


















'? 




•^ 


s 


c 


u 


'V 






5 


V 


c 


s 





<u 


3 






•0 


1^ 


p 


^ 


c3 


^^ 


1 





-3 


1 

s 


4J 


. a 


§ 


fl 


3 
3 


!3 






3 


^ 




s 


ucn 


aj ° 


S 


d 


d 


^ 


c 


^^ 





E 







^ 


^ 


207 


20 


^ 


40 






56 


24 


44 


208 


20 


# 


40 






64 


24 


44 


209 


20 


¥ 


40 






72 


24 


44 


210 


21 


^\ 














211 


16 


A 


64 






28 


44 




212 


43 


:r\ 


86 


24 


24 


48 






213 


27 


iV 


72 






40 


44 




214 


20 


# 


40 


56 


32 


64 




24 


215 


43 


^/ 














216 


27 


h 














217 


21 


A 


48 






64 


24 


44 


218 


16 


A 


64 






56 


24 


44 


219 


21 


^> 


28 






48 


24 


44 


220 


33 


♦ 














221 


17 


TT 


24 






24 


56 




222 


18 


A 


24 






72 


44 




223 


43 


¥ 


86 


48 


24 


64 




24 


224 


18 


* 


24 






64 


44 




225 


27 


fy 


24 






40 


24 


44 


226 


18 


t\ 


24 






56 


44 




227 


49 


¥ 


56 


64 


28 


72 






228 


18 


¥ 


24 






48 


44 




229 


18 


tV 


24 






44 


48 




230 


23 


¥ 














231 


18 


* 


32 






48 


44 




232 


29 


2% 














^i2> 


18 


-'^ 


48 






56 


44 




234 


18 


j\ 


24 






24 


56 




235 


47 


iS 














236 


18 


t\ 


48 






32 


44 




237 


18 


1% 


48 






24 


44 




238 


18 


A 


72 






24 


44 




239 


18 


A 


72 


24 


64 


32 






240 


18 


tV 














241 


18 


♦ 


72 


24 


64 


32 




24 


242 


18 


A 


72 






24 


24 


44 


243 


18 


A 


64 






32 


24 


44 


244 


18 


T^^ 


48 






32 


24 


44 


245 


49 


A 














?46 


18 


tV 


24 






24 


24 


44 


247 


18 


t\ 


48 






56 


24 


44 



i7« 



MILLING AND MILLING CUTTERS 



.2 




"o 


g 


No. I 


Hole 


Ji 
^ 


Idlers 


'> 










p 


S 


c 








u 

a 


•S 






u 


X 




o*-i 




u 

4) 




C/3 

c 


ni 


'0 

K 
6 


"o 

W 

N 

6 


1 


c 


^ 





S 


c^ 





^ 


Z 


248 


31 


A 














249 


18 


♦ 


32 






48 


24 


44 


250 


18 


A 


24 






40 


24 


44 


251 


18 


t\ 


48 


44 


32 


64 




24 


252 


18 


♦ 


24 






48 


24 


44 


253 


33 


¥ 


24 






40 


56 




254 


18 


tV 


24 






56 


24 


44 


255 


18 


♦ 


48 


40 


24 


72 




24 


256 


18 


A 


24 






64 


24 


44 


257 


49 


^ 


56 


48 


28 


64 




24 


258 


43 


^^ 


32 






64 


24 


44 


259 


21 


ih 


24 






72 


44 




260 


39 


♦ 














261 


29 


/^ 


48 


64 


24 


72 






262 


20 


2^^ 


40 






28 


44 




263 


49 


^^ 


56 


64 


28 


72 




24 


264 


33 


3% 














265 


21 


A 


56 


40 


24 


72 






266 


21 


* 


32 






64 


44 




267 


27 


^ 


72 






32 


44 




268 


21 


A 


28 






48 


44 




269 


20 




64 


32 


40 


28 




24 


270 


27 














271 


21 


A 


56 






72 


24 




272 


21 


♦ 


56 






64 


24 




273 


21 


A 


24 






24 


56 




274 


21 


2\ 


56 






48 


44 




275 


21 


■2^T 


56 






40 


44 




276 


21 


Y^T 


56 






32 


44 




277 


21 


/r 


56 






24 


44 




278 


21 


A 


56 


32 


48 


24 






279 


27 


oV 


24 






32 


24 


44 


280 


49 


iV 














•281 


21 


^T 


72 


24 


56 


24 




24 


282 


43 




86 


24 


24 


56 






283 


21 


A 


56 






24 


24 


44 


284 


21 


?T 


56 






32 


24 


44 


285 


21 


A 


56 






40 


24 


44 


286 


21 


^^ 


56 






48 


24 


44 


287 


21 


/t 


24 






24 


24 


44 


288 


21 


A 


28 






32 


24 


44 



PLAIN AND DIFFERENTIAL INDEXING 179 



§ 








No. 


I Hole 




Idlers 


'53 
















'> 




"o 


s 


a 


^^ 


n3 






s 





S 


S 





2 


C 






-z 


"S 


3 


^ 




^^ 


*cf 


"o 


-B 


1 

s 

3 


1 


Ol-H 


§ 
c3 


^1 


3 




3 


M 
d 


6 


z 


l-l 


^ 





E 


C^ 





^ 


^ 


289 


21 


# 


56 






72 


24 


44 


290 


29 


A 














291 


15 




'40 






48 


44 




292 


21 


rr 


28 






48 


24 


44 


293 


15 


T^3 


48 


32 


40 


56 






294 


21 


A 


24 






48 


24 


44 


295 


15 


A 


48 






32 


44 




296 


37 


aV 














297 


33 


A 


28 


48 


24 


56 






298 


21 


¥ 


28 






72 


24 


44 


299 


23 


A 


24 






24 


56 




300 


15 


t!^ 














301 


43 


^^ 


24 






48 


24 


44 


302 


16 


A 


32 






72 


24 




303 


15 


A 


72 


24 


40 


48 




24 


304 


16 


♦ 


24 






48 


44 




305 


IS 


i\ 


48 






32 


24 


44 


306 


15 


♦ 


40 






32 


24 


44 


307 


15 


A 


72 


48 


40 


56 




24 


308 


16 


¥ 


32 






48 


44 




309 


15 


¥ 


40 






48 


24 


44 


310 


31 


A 














311 


16 


A 


64 


24 


24 


72 






312 


39 


^V 














3^3 


16 


A 


32 






28 


56 




314 


16 


1^6 


32 






24 


56 




315 


16 


T6 


64 






40 


24 




316 


16 


T^ 


64 






32 


44 




317 


16 


TS 


64 






24 


44 




318 


16 


t\ 


56 


28 


48 


24 






319 


29 


2% 


48 


64 


24 


72 




24 


320 


16 


T6 














321 


16 


? 


72 


24 


64 


24 




24 


322 


23 


2\ 


32 






64 


24 


44 


323 


16 


♦ 


64 






24 


24 


44 


324 


16 


* 


64 






32 


24 


44 


325 


16 


t\ 


64 






40 


24 


44 


326 


16 


TS 


32 






24 


24 


44 


327 


16 


^ 


32 






28 


24 


44 


328 


41 


A 














329 


16 


tV 


64 


24 


24 


72 




24 



i8o 



MILLING AND MILLING CUTTERS 



1 








No. 


[ Hole 




Idlers 


i> 




"o 


g 


fl 


^ 


'a 






Q 


u 


fl 


S 





S 


a 








"S 




> 







"0. 


u 


9) 


o 


a 


3 


;> 


Si 


-d 


en 


"o 


"3 


1 


'0 


-of 





-1 


if 


§ 


M 




3 


? 


Ct-t 


S 


.S<^ 


u ° 


aj 


d 


Q 


^ 


eS 


^ 





s 


c^ 





^ 


^ 


330 


33 


sir 














331 


16 


* 


64 


44 


24 


48 




24 


332 


16 


T^ 


32 






48 


24 


44 


333 


18 


l\ 


24 






72 


44 




334 


16 


t\ 


32 






56 


24 


44 


335 


33 


j\ 


72 


48 


44 


40 




24 


336 


16 


l\ 


32 






64 


24 


44 


337 


43 


^\ 


86 


40 


32 


56 






338 


16 


1% 


32 






72 


24 


44 


339 


18 


V 


24 






56 


44 




340 


17 


tV 














341 


43 


4%. 


86 


24 


32 


40 






342 


18 


t\ 


32 






64 


44 




343 


15 


l\ 


40 


64 


24 


86 




24 


344 


43 


fs 














345 


iS 


T% 


24 






40 


56 




346 


18 


^> 


72 


56 


32 


64 






347 


43 


^3 


86 


24 


32 


40 




24 


348 


18 


If 


24 






32 


56 




349 


18 


tV 


72 


44 


24 


48 






350 


18 


A 


72 


40 


32 


64 






351 


18 


t\ 


24 






24 


56 




352 


18 


A 


72 


24 


24 


64 






353 


18 


A 


72 






56 


24 




354 


18 


^ 


72 






48 


24 




355 


18 


rs 


72 






40 


24 




356 


18 


^s 


72 






32 


24 




357 


18 


i\ 


72 






24 


44 




358 


18 


T% 


n 


32 


48 


24 






359 


43 


tV 


86 


48 


32 


100 




24 


360 


18 


T8 














361 


19 


t\ 


32 






64 


44 




362 


18 


t\ 


72 


28 


56 


32 




24 


363 


18 


t\ 


72 






24 


24 


44 


364 


18 


A 


72 






32 


24 


44 


365 


26 


2% 


32 


48 


24 


56 






366 


18 


A 


48 






32 


24 


44 


367 


18 


T% 


72 






56 


24 


24 


368 


18 


t\ 


72 


24 


24 


64 




24 


369 


41 


A 


32 


56 


28 


64 






370 


37 


/y 















PLAIN AND DIFFERENTIAL INDEXING l8l 



1 




"0 


s 


No. I 


Hole 




Idlers 


!> 




g 








'0 


1 


1 

c 





1- 

-OT3 


.S 


1 






1 


11 


t 


si 


0-2 




6 


d 


ll 


c 


^ 





£ 


^ 





^ 


^ 


371 


21 


2\ 


32 


56 


24 


64 






372 


18 


tV 


48 






64 


24 


44 


373 


20 


^ 


40 


48 


32 


72 






374 


18 


tV 


72 


64 


32 


56 




24 


375 


18 


T^ 


24 






40 


24 


44 


376 


47 


V 














377 


29 


2^ 


24 






24 


56 




378 


18 


A 


32 






64 


24 


44 


379 


20 


^% 


48 


56 


40 


72 






380 


19 


T9 














381 


18 


t\ 


24 




■ 


56 


24 


44 


382 


20 


i~0 


40 






72 


24 




383 


20 


2\ 


40 






681 


44 




384 


20 


2\ 


40 






64 


44 




385 


20 


t^ 


32 






48 


44 




386 


20 


^\ 


40 






56 


44 




387 


43 


t\ 


32 


56 


28 


64 






388 


20 


-io 


40 






48 


44 




389 


20 


2/ 


40 






44 


56 




390 


39 


¥ 














391 


20 


2^0 


48 


24 


40 


72 






392 


49 


4^ 














393 


20 


/o 


40 






28 


44 




394 


20. 


2S 


40 






24 


56 




395 


20 


■^ 


64 






32 


44 




396 


20 


?^ 


56 


28 


40 


32 






397 


20 


2/ 


64 


24 


40 


32 






398 


20 


2^0 


100 


40 


64 


32 






399 


21 


¥ 


32 






64 


44 




400 


20 


-h 














401 


21 


i-T 


56 


32 


24 


76 1 






402 


21 


2T 


28 






48 


44 


. 


403 


20 


♦ 


64 


24 


40 


32 




24 


404 


20 


♦ 


72 


24 


40 


48 




24 


405 


20 


2^0 


64 






32 


24 


44 


406 


20 


# 


40 






24 


24 


44 


407 


20 


2% 


40 






28 


24 


44 


408 


20 


^^0 


40 






32 


24 


44 


409 


20 


2^0 


40 


24 


32 


48 




24 


410 


41 


t\ 















Note. Special gears in this and following tables are 46, 47, 52, 58, 
68, 70, 76, 84. 1 Special gear. 



l82 



MILLING AND MILLING CUTTERS 



o 

'53 




g 


1 

g 


No. 1 


Hole 


■a 

in 
% 


Idlers 


1 

1 






1 




S 

3 




"^"B 

o^-" 


s 


12 00 


c 


% 


6 


6 


"A 


c 


!2; 





E 


^ 





^ 


^ 


411 


21 


^T 


28 






24 


56 




412 


20 


2V 


40 






48 


24 


44 


413 


21 


¥ 


48 






32 


44 




414 


21 


56 






32 


44 




415 


20 


?o 


32 






48 


24 


44 


416 


20 


2V 


40 






64 


24 


44 


417 


21 


^\ 


56 


32 


48 


24 






418 


20 


-/o 


40 






72 


24 


44 


419 


33 


¥ 


44 


28 


24 


72 






420 


21 


/t 














421 


20 


^0 


48- 


56 


40 


72 




24 


422 


20 


2^7 


40 


44 


32 


64 




24 


423 


21 


A 


72 


24 


56 


48 




24 


424 


43 


t\ 


86 


24 


24 


48 






425 


21 


2T 


72 


48 


56 


40 




24 


426 


21 


^J 


56 






32 


24 


44 


427 


20 


2^U 


40 


48 


32 


72 




24 


428 


20 


2V 


40 


56 


32 


64 




24 


429 


21 


A 


28 






24 


24 


44 


430 


43 


/it 














431 


21 


-h 


72 


44 


28 


48 




24 


432 


20 


2%- 


40 


56 


28 


64 




24 


433 


20 


1^^ 


40 


44 


24 


72 




24 


434 


21 


A 


48 






64 


24 


44 


435 


21 


2T 


28 






40 


24 


44 


436 


20 


i-. 


40 


48 


24 


72 




24 


437 


23 


-h 


32 






64 


44 




438 


21 


A 


28 






48 


24 


44 


439 


43 


¥ 


86 


24 


24 


72 




24 


440 


33 


3^3 














441 


21 


ii 


32 






64 


24 


44 


. 442 


20 


2% 


40 


56 


24 


72 




24 


443 


20 


2V 


40 


48 


24 


86 




24 


444 


21 


^T 


56 


48 


24 


64 




24 


445 


33 


3\ 


64 


32 


44 


40 




24 


446 


33 


-h 


44 






24 


24 


48 


447 


21 


A 


28 






72 


24 


44 


448 


20 


2^0 


40 


64 


24 


72 




24 


449 


33 


A 


64 


32 


44 


72 




24 


450 


33 


3V 


44 






40 


24 


32 



PLAIN AND DIFFERENTIAL INDEXING 



^83 



1 




"0 




No. I 


Hole 




Idlers 


*> 

p 


c 


t 






"^ 


Ji 


a 


jj. 








"a 


_o 


lU 





H 


3 




c3 


•-H 


CO 


"0 


-3 


x^ 


'0 


H X 


c 




0^ 


3 


c 



K 


W 


6 

3 




11 


cS 


tB, 


c 
a 


03 


6 


6 


^ 




l-H 


z 





E 


CA) 





^ 


'^ 


451 


33 


3 
3 3 


24 






24 


24 


44 


452 


33 


FS 


44 






48 


24 


40 


453 


33 


-h 


44 






52^ 


24 


40 


454 


49 


4\ 


56 


64 


28 


72 






455 


49 


-.^ 


28 


40 


32 


64 






456 


21 


^T 


56 


64 


24 


72 




24 


457 


33 


33 


44 






681 


24 


40 


458 


33 


il 


44 






72 


24 


24 


459 


27 


^'V 


24 


48 


24 


72 






460 


23 


2T 














461 


33 


3\ 


44 


28 


24 


72 




24 


462 


33 


i. 


32 






64 


24 


44 


463 


21 


-h 


56 


64 


24 


86 




24 


464 


33 


A 


44 


48 


28 


56 




24 


465 


33 


-h 


44 


24 


24 


100 




24 


460 


49 


4 
4 9 


56 


48 


28 


64 






467 


33 


A 


44 


48 


32 


72 




24 


468 


39 


3 

31 


28 


48 


24 


56 






469 


49 


¥ 


28 






48 


44 




470 


47 


/r 














471 


49 


/. 


56 


32 


28 


76 1 






472 


49 


*V 


56. 


32 


28 


72 






473 


33 


I3 


48 


64 


32 


72 




24 


474 


49 


l\ 


56 


32 


28 


64 






475 


49 


l\ 


56 


40 


28 


48 






476 


49 


t\ 


56 






64 


24 




477 


27 


iV 


24 


48 


24 


56 






478 


49 


¥ 


56 


24 


28 


64 






479 


49 


¥ 


56 


32 


28 


44 






480 


49 


tV 


56 


32 


28 


40 






481 


37 


aV 


24- 






24 


56 




482 


33 


3\ 


44 


56 


24 


72 




24 


483 


49 


^S 


56 






32 


44 




484 


49 


¥ 


56 


24 


28 


32 






48s 


23 


^/ 


46 1 


24 


24 


100 




24 


486 


27 


-ii 


32 


56 


28 


64 






487 


39 


-h 


24 


72 


52^ 


44 






488 


33 


~h 


44 


64 


24 


72 




24 


489 


23 


* 


46^ 


58^ 


Z^ 


64 




24 


490 


49 


4V 















Special gear. 



1 84 



MILLING AND MILLING CUTTERS 



1 




"o 




No. I 


Hole 




Idlers 


1 


§ 










1 


^2 


1 


0, 


<u 



3 


a 
a 


1 


1 




2 


°'§ 




tt2 


C 

c 




M 


<N 




"2 


01— ' 




utn 


« ° 


s 


d 


6 


z 


a 


^ 





E 







^ 


1 


491 


33 


A 


44 


681 


24 


72 




24 


492 


41 


A 


28 


48 


24 


56 






493 


29 


^^9 


32 


64 


24 


72 






494 


39 


3\ 


32 






64 


44 




495 


27 


^ 


32 


40 


24 


64 






496 


49 


t\ 


56 


24 


28 


32 




24 


497 


49 


-A 


56 






32 


24 


44 


498 


27 


-ii 


48 


56 


24 


64 






499 


49 


^9 


56 


24 


28 


48 




24 


500 


49 


.?% 


56 


32 


28 


40 




24 


501 


49 


^\ 


56 


32 


28 


44 




24 


502 


49 


i-. 


56 


32 


28 


48 




24 


503 


23 


A 


46^ 


64 


32 


86 




24 


504 


49 


?% 


56 






64 


24 


24 


505 


49 


^\ 


56 


40 


28 


48 




24 


506 


49 


t\ 


56 


32 


28 


64 




24 


507 


39 


-h 


24 






24 


56 




508 


49 


?\ 


56 


32 


28 


72 




24 


509 


49 


?*^ 


56 


32 


28 


76 1 




24 


510 


49 


/^ 


56 


40 


28 


64 




24 


511 


49 


t\ 


28 






48 


24 


44 


512 


49 


■^s 


56 


44 


28 


64 




24 


513 


27 


■i. 


32 






64 


44 




514 


49 


■i-. 


56 


48 


28 


64 




24 


515 


27 


iV 


72 


32 


24 


100 






• 516 


43 


Tj 


32 


56 


28 


64 






517 


49 


^/ 


56 


48 


28 


72 




24 


518 


49 


t\ 


28 






64 


24 


44 


519 


27 


^ 


72 


56 


32 


64 






520 


39 


3V 














521 


27 


2V 


72 


76 1 


•48 


64 






522 


29 


■i^ 


48 


64 


24 


72 






523 


27 


V 


72 


681 


48 


64 






524 


27 


iy 


72 


32 


24 


64 






525 


27 


-ij 


72 


40 


32 


64 






526 


49 


A 


56 


64 


28 


72 




24 


527 


31 


A 


32 


64 


24 


72 






528 


27 


2V 


72 


24 


24 


64 






529 


27 


/r 


72 


44 


48 


64 






530 


15 


tV 


24 


56 


32 


64 







Special gear. 



PLAIN AND DIFFERENTIAL INDEXING 



i8S 



1 




*© 


^ 


No. I 


Hole 




Idlers 


> 










^o 




is 


1 


rt'S 


h 


"I- 


"o 


"o 




'0 


?2 


§ 


S 3 
1^ c 


3 

c 




\ 






"H 


d 




ii; 


iri '=> 





6 


6 


1 


c 


^ 





(i( 


c^ 





^ 


^ 


531 


27 


ij 


72 






48 


24 




532 


27 


2T 


72 


32 


48 


64 






533 


27 


21 


72 


32 


48 


56 






534 


27 


V 


72 






32 


44 




535 


27 


-h 


72 


32 


48 


40 






536 


39 


-h 


52' 






64 


24 


44 


537 


27 


-h 


72 


28 


56 


32 






538 


29 


^9 


58^ 


56 


24 


72 






539 


49 


V 


28 


48 


24 


56 




24 


540 


27 


2V 














54T 


39 


¥ 


52^ 


56 


32 


48 




24 


542 


39 


¥ 


52^ 


44 


32 


64 




24 


543 


27 


2V 


72 


24 


48 


32 




24 


544 


15 


tV 


40 


56 


24 


64 






545 


15 


T^3 


32 


44 


24 


64 






546 


39 


3^^ 


32 






64 


24 


44 


547 


27 


^V 


72 


32 


48 


56 




24 


548 


27 


^ 


72 


32 


48 


64 




24 


549 


27 


V 


72 






48 


24 


24 


550 


15 


¥ 


32 


40 


24 


64 






551 


29 


2^ 


32 






64 


44 




552 


27 


-h 


72 


24 


24 


64 




24 


553 


49 


?\ 


28 


48 


24 


72 




24 


554 


27 


2\ 


72 


56 


48 


64 




24 


555 


15 


¥ 


24 






72 


44 




556 


15 


¥ 


24 


44 


40 


64 






557 


15 


tV 


40 


32 


24 


86 






558 


27 


9 
¥ 


48 






64 


24 


44 


559 


39 


3^ 


24 






72 


24 


44 


560 


43 


?\ 


86 


40 


32 


64 






561 


27 


-h 


72 


56 


32 


64 




24 


562 


27 


ii 


72 


44 


24 


64 




24 


563 


29 


¥ 


58 1 






681 


44 




564 


43 




86 


24 


24 


56 






56s 


15 


tV 


24 






56 


44 




566 


43 


¥ 


86 


24 


24 


44 






5^Z 


15 


tV 


32 


44 


40 


64 






568 


15 


tV 


40 


32 


24 


64 






569 


29 


/^ 


58^ 






44 


24 




570 


15 


tV 


32 






64 


44 





1 Special gear. 



i86 



MILLING AND MILLING CUTTERS 



.2 




'o 


s 


No. I 


Hole 


— 


Idlers 


■> 












'0 






g 





.1 


'S- 

(3 






1 


3 


^3 


Is 


l-l 


|l 


11 


H 


H 

6 


6 


'iZ, 


d 


^ 





plH 


C/2 





^ iz; 


571 


43 


_3_ 


86 


28 


64 


32 






572 


15 


T5 


40 


28 


24 


64 






573 


15 


tV 


40 






72 


24 




574 


41 


l\ 


32 






64 


24 


44 


575 


15 


tV 


24 






40 


44 




576 


15 


tV 


40 






64 


24 




577 


43 


A 


86 


32 


64 


44 




24 


578 


15 


¥ 


48 


44 


40 


64 






579 


15 


2% 


40 






56 


44 




580 


29 


VV 














581 


15 


tV 


48 


32 


40 


76 1 






582 


15 


2V 


. 40 






48 


44 




583 


27 


tV 


72 


64 


24 


86 




24 


584 


15 


tV 


48 


32 


40 


64 






585 


15 


tV 


24 






24 


56 




586 


15 


^^ 


72 


48 


40 


56 






587 


29 


tV 


58^ 






28 


24 


44 


588 


15 


tV 


40 






32 


44 




589 


15 


tV 


72 


44 


40 


48 






590 


15 


¥ 


48 






32 


44 




591 


15 


¥ 


40 






24 


44 




592 


16 


tV 


24 






72 


44 




593 


15 


tV 


72 


28 


40 


48 






594 


35 


3¥ 


32 


56 


28 


64 






595 


15 


¥ 


72 






24 


44 




596 


15 


¥ 


72 


24 


40 


32 






597 


33 


A 


44 


56 


24 


72 






598 


16 


tV 


64 


S6 


24 


72 






599 


43 


A 


86 


44 


24 


84 




24 


600 


15 


tV 














601 


29 


^v 


58^ 


56 


48 


72 




24 


602 


43 


A 


32 






64 


24 


44 


603 


15 


tV 


72 


24 


40 


24 




24 


604 


16 


¥ 


32 






72 


24 




605 


15 


tV 


72 






24 


24 


44 


606 


15 


tV 


72 


24 


40 


48 




24 


607 


15 


tV 


■ 72 


28 


40 


48 




24 


608 


16 


A 


32 






64 


44 




609 


15 


tV 


40 






24 


24 


44 


610 


15 


tV 


48 






32 


24 


44 



Special gear. 



PLAIN AND DIFFERENTIAL INDEXING 187 



.1 




"o 




No. I 


Hole 


■a 


No. 2 


Hole 


'> 












1 


3 


1 


1 


L 


fl 


crj 

c 





M 

6 


E 
6 


^ 


C 


"^ 





E! 







^ 


^ 


611 


15 


¥ 


72 


44 


40 


48 




24 


612 


15 


tV 


40 






32 


24 


44 


613 


16 


tV 


64 


48 


32 


72 






614 


15 


tV 


72 


48 


40 


56 




24 


615 


15 


tV 


24 






24 


24 


44 


616 


16 


tV 


32 






48 


44 




617 


33 


3J 


44 


32 


24 


86 






618 


15 


tV 


40 






48 


24 


44 


619 


16 


T> 


48 


28 


2>2 


72 






620 


31 


3^ 














621 


15 


T^T 


40 






56 


24 


44 


622 


16 


tV 


64 


24 


24 


72 






623 


16 


tV 


64 


24 


24 


681 






624 


16 


iV 


24 






24 


56 




625 


15 


tV 


24 






40 


24 


44 


626 


16 


tV 


32 






28 


56 




627 


15 


tV 


40 






72 


24 


44 


628 


16 


tV 


32 






24 


56 




629 


16 


tV 


64 






44 


24 




630 


16 


tV 


64 






40 


24 




631 


16 


tV 


64 


28 


56 


72 






632 


16 


tV 


64 






32 


44 




633 


16 


tV 


64 






28 


44 




634 


16 


tV 


64 






24 


44 




635 


15 


I^^ 


24 






56 


24 


44 


636 


16 


tV 


56 


28 


48 


24 






637 


49 


1¥ 


24 






24 


56 




63S 


29 


lj'9 


48 


64 


24 


72 




24 


639 


33 


A 


44 


28 


32 


64 






640 


16 


tV 














641 


33 


A 


44 


32 


48 


76 1 






642 


16 


tV 


72 


24 


64 


24 




24 


643 


16 


V 


64 


28 


56 


24 




24 


644 


49 


¥ 


56 






32 


44 




645 


15 


1^ 


24 






72 


24 


44 


646 


16 


tV 


64 






24 


24 


44 


647 


16 


tV 


64 






28 


24 


44 


648 


16 


^ 


64 






32 


24 


44 


649 


33 


3^ 


72 






48 


24 




650 


16 


tV 


64 






40 


24 


44 



Special gear. 



MILLING AND MILLING CUTTERS 



.2 








No. I 


Hole 




No. 2 


Hole 


5 
1 




1 


1 

§ 


§ 

Ot3 




d 

c 





1 


B 

3 


i 


01— 1 


2 




lg 


8 


d 


d 


^ 


£ 


^ 





E 







^ 


^ 


651 


16 


tV 


64 






44 


24 


24 


652 


16 


T6 


32 






24 


24 


44 


653 


33 


s\ 


72 


28 


44 


48 






654 


16 


tV 


64 






56 


24 


44 


655 


16 


^. 


64 


40 


32 


48 




24 


656 


16 


tV 


24 






24 


24 


44 


657 


18 


tV 


32 


48 


24 


56 






658 


16 


tV 


64 


24 


24 


72 




24 


659 


16 


tV 


64 


24 


24 


76 1 




24 


660 


33 


l\ 














661 


16 


tV 


64 


56 


48 


72 




24 


662 


16 


tV 


64 


44 


24 


48 




24 


663 


17 


tV 


24 






24 


56 




664 


16 


tV 


32 






48 


24 


44 


665 


49 


?v 


56 






40 


24 


44 


666 


18 


tV 


24 






72 


44 




667 


16 


tV 


64 


48 


32 


72 




24 


668 


16 


tV 


32 






56 


24 


44 


669 


33 


¥ 


44 






24 


24 


24 


670 


33 




72 


48 


44 


40 




24 


671 


33 


72 






48 


24 


24 


672 


18 


s 


24 






64 


44 




673 


16 


tV 


48 


44 


32 


72 




24 


674 


33 


A 


72 


56 


44 


48 




24 


675 


33 


A 


44 






40 


24 


24 


676 


16 


tV 


32 






72 


24 


44 


677 


18 


tV 


48 


32 


24 


86 






678 


18 


tV 


24 






56 


44 




679 


49 


^% 


28 






44 


24 


40 


680 


17 


tV 














681 


33 


A 


44 






56 


24 


24 


682 


33 


A 


48 






64 


24 


24 


683 


16 


tV 


32 






86 


24 


44 


684 


18 


tV 


32 






64 


44 




685 


18 


tV 


24 


56 


48 


40 






686 


15 


tV 


40 


64 


24 


86 




24 


687 


18 


tV 


24 






44 


48 




688 


16 


tV 


24 






72 


24 


44 


689 


39 


A 


24 


48 


24 


56 






690 


18 


tV 


24 






40 


56 





Special gear. 



PLAIN AND DIFFERENTIAL INDEXING 189 



1 


1 

'6 
'2 


L 
4^ 


1 
§ 

c3 


No. I 


Hole 




Idlers 


1 


§ 
i-i 

a 

Ox) 




1 

6 


K 
6 


1 


c 


;? 





E 


C/2 





i 


i 


691 


18 


tV 


48 


32 


24 


58^ 






692 


18 


tV 


72 


56 


32 


64 






693 


18 


tV 


32 






48 


44 




694 


17 


tV 


681 






56 


24 


44 


695 


18 


tV 


72 


24 


24 


100 






696 


18 


tV 


24 






32 


56 




697 


17 


V 


24 






24 


24 


44 


698 


18 


IV 


72 


44 


24 


48 






699 


18 


¥ 


48 






56 


44 




700 


18 


tV 


72 


40 


32 


64 






701 


17 


tV 


681 


48 


32 


56 




24 


702 


18 


tV 


24 






24 


S6 




703 


19 


t\ 


24 






72 


44 




704 


18 


tV 


72 


24 


24 


64 






705 


18 


tV 


48 






40 


44 




706 


18 


V" 


72 






56 


24 




707 


18 


j\ 


72 






52^ 


24 




708 


18 


? 


72 






48 


24 




709 


18 


V 


72 






44 


24 




710 


18 


tV 


72 






40 


24 




711 


18 


tV 


64 






32 


44 




712 


18 


^> 


72 






32 


24 




713 


18 


¥ 


72 






28 


44 




714 


18 


tV 


72 






24 


44 




715 


18 


tV 


72 


32 


64 


40 






716 


18 


tV 


72 


28 


56 


32 






717 


18 


tV 


72 


24 


64 


32 






718 


33 


3T 


44 


58^ 


24 


64 




24 


719 


17 


tV 


68 1 


52^ 


24 


72 




24 


720 


18 


tV 














721 


21 


¥ 


24 


64 


32 


681 






722 


19 


¥ 


32 






64 


44 




723 


18 


tV 


72 


24 


64 


32 




24 


724 


18 


tV 


72 


28 


56 


32 




24 


725 


18 


tV 


72 


24 


48 


40 




24 


726 


18 


tV 


72 






24 


24 


44 


727 


18 


tV 


72 






28 


24 


44 


728 


18 


¥ 


72 






32 


24 


44 


729 


18 


tV 


64 






32 


24 


44 


730 


20 


2V 


32 


48 


24 


56 







Special gear. 



igo 



MILLING AND MILLING CUTTERS 



J 


M 


« 


fO 


-+ 


>o 


\n 


J^ 


on 


Ov 


o 




m 


^ 


m 


VO 


t~- 


oo Ov 


o 




N ro ^ 




































M IH 








w 
















































<N 




o 


•^ 


Ov 




t^ 


o 


in Ov 




I^ 


H 


in 


Ov 




IN 


VO 


O t 00 




































t^ r^ 




















































o 





o 


o 




M 




w 














rn 














o 


o 


o 


o 


o 


o 


o 





o 


o 


O O 


o 


o 


o 


o 


o 


O O 


o 


O 


COO 










M 








<N 


in 




O ro 






IH 




r^ 


o m 


in 




M -+ VO 








CO 




V) 


r^ 


rt) 




M 








r^ 
















r^ 




•m- 




on 








r^ 


Ov 




<n in 




Ov 






O 






■+ 


O CO M 














M 


HI 






w 




O) 




fi 










■^ 






o 


o 


o 


C 


o 








O 


o 


o 


O O 


o 





o 


o 


o 


o 


O 


o 


O O 




r<- 


vr, 


00 


n 


m 


m 


ca 


.R 


m 


o 


00 M 


m 


VO 


00 


M 


rt 


vO Ov 


IH 


^ 


O Ov w 


















i^ 






























8^ 








on 




m t^ 








1^ 




^ 5 








'^ 


o 


o 


O 


M 


M 














m 


rO 


m 






■^1- 






o 


o 


O 


o 


O 


o 





O 


O 


o 


O O 


o 


o 


o 


o 


o 


O 


o 

00 


o 


_o_P_P__ 

VO d '=}• 




rf 


no 


IS 


-.(-) 


o 


m 


t-~ 


^ 


in 


Ov 


m t-~ 


M 


m 


Ov 


IV, 


VO 


Rv s; 
































Rv 
















r^ 


? 




M- 


t- 


n\ 






















^ 


o 


o 


O 


M 








o 


p< 




rO 


m 


m 




^ 


•^ ^ 


M- 


I/) 






o 


o 


O 


o 


o 


O 


o 


o 


O 


o 


o o 


o 


o 


O 


O 


o 


o o 


O 


o 


6 6 6 ■ 












rN 






M 






M t^ 




o 


VO 


rn 


Ov 


in (s 


00 


m 


w r- ^ 








VD 




rn 


m 










<N I^ 












M r^ 








































^ 












o 


o 


O 




H 




M 










CO 


ro 


r'J 




^ •* 


m 




in lo VO 




o 


o 


o 


o 


O 


O 


o 


o 


O 


o 


o o 





O 


o 


O 


o 

VO 


_o_o_ 


_o 


_o_ 


_.o_o_o_ 






„ 


„ 


,_, 


H 


r) 


IS 


(>l 








■* 
















fi 






Ov 


VO 




o 


t^ Tj- 




00 








VO rn 


O 


r^ 












m 
































^0 


o 


o 












N 




(M 


N ro 


WJ 


r*! 


1- 


■* 


^ 


tt m 






in VO VO 




o 


o 


o 


o 


O 


O 


O 


o 


O 


o 


o o 


o 


O 


o 


O 


o 


O O 


O 


O 


COO 




rn 


^o 


OS 


N 






M 




r^ 


o 




Ov 


M 


in 


00 


M 




o 


m 


VO Ov <N 










M 












rn 










•^ 
























oo 




^ 


t^ 


o 


fO VO 








oo 




t t^ 






VO Ov <N 




o 


o 


o 


M 


M 




Ot 




M 






r-J 




■^ 


■* 


m 




VO 








o 


o 


o 


o 


o 


o 


o 


o 


o 


o 


o o 


o 


O 


O 


O 


O 


o o 


O 


O 


o o o 






in 


rT) 


^ 




m 


oo 


w 




VO 




^ 


-o 


Ov 


M 


"t 


VO Ov 


0) 


Ti- 


t^ O. r. 








o> 










!< 






























o> 
























o5 w 




r^ 






o 


o 


O 








CN 


M 




rn 










m 


i/> 








r^ r^ t^ 




o 


o 


o 


O 


o 


O 


O 


o 


o 


o 


o o 


o 


o 


o 


O 


o 


o 


O 


O 


O O O 




lO 


o 




o- 


T1- 


Ov 




Cv 


r^, 


00 


fn oo 


m 


(^ 


<s 


r^ 


M 


I^ (N 


j^ 


IH 


VO H VO 




T)- 




ro 














































r^ 






t^ 






J^ HI 




















C) 


o 


o 




M 


w 






M 


r'i 


fj 


"O -^ 
















t^ 


t->. !>. 00 




o 





O 


o 


_o_ 


_o_ 






o 


o 


o o 


O 


o 


O 


O 


o 


_<^-__o_ 


r- 


_o_ 


o o o 

00 Ov 00 




o 


„ 


„ 


IH 


m 


m 


'T < 


m 


in 


m 


^ 








































t^ 












•* 00 






Ov 






O -i- 


00 






Ov 




VO o 


t 






01 


o 


o 


M 




M 


C-l 


M 




c<. 








Uj 










t^ 


I^ 






d 


o 


o 


o 


o 


O 


o 


O 


O 


o 


o o 


O 


O 


O 


O 


o 


o o 


O 


o 


6 6 6 






o 


^ 


Oi 


tT 


^ 


m 


on 


m 


on 


rn f- 


r< 


r^ 


N 


1^ 


M 


VO w 


% 


o 


in 














Tt 


r^ 




























=§ 


N-1 










^ 






t-» n 






















o 




M 


(N 






tn 


^0 


■* 


•* in 




vO 


vO 


VO 


r^ 


r- CO 


CXJ 








o 


o 


o 


o 


o 


o 


O 


o 


O 


o 


o o 


O 


o 


o 


o 


O 


O O 


o 


o 


O 






<s 




Tt 


M 


r^ 




o 


VO 


(V) 


CO ^ 


a 


vO 




o. 




















R 






















A 














^ 














r^ 


r> r- 










00 Ov 










o 




M 


r« 








Tf 




m in 




VO 


r- 


t^ 


ou 


Ov 








d 


o 


o 


o 


O 


O 


O 





o 


O 


O 


o 


o 


O 


o 


O 


o 


o 








s 


^ 


R 


R 


R 


^ 


R 


g 


R 


g 


R R 


R 


R 


R 


g 


R 


R R 








O 


in 


6 


in 





















6 








O m 










o 
























1^ 


















d 


o 


o 


o 


o 


O 


o 


o 


d 


o 


n o 


o 


o 


o 


o 


o 


O O 












,^ 






rs 




^ 


M 


i^ 


■^ 


Ov o 


r-1 




in 


H 


t^ 


















o 














oo M 






Ov 




^ 










0\ 


































rl- 










o 




M 


N 




ro 




-^ 




m 








t^ 




(JJ 












d 


o 


o 


o 


O 


O 


o 


o 


o 





o o 


O 


o 


o 


o 


o 


O 










tJ-> 


M 


o 


(N 


t^ 


fn 


00 




o 


in 


i-v VO 


M 


t^ 


rn 


CO 






















^~ 


























































f^ 


















o 


M 


M 


0) 


M 










Kj 




f^ 


l-~ 


















o 


o 


o 


o 


O 


O 


o 


o 


o 


O 


o o 


O 


o 


O 


o 


o 












00 


vO 


in 


m 


„ 


Ov 


en 


o 


■^ 


(N 


w Ov 


^^ 


o 


'^ 


ri 


































t^ m 






























Ov 






I^ 






■* O 




















M 


o 


M 








c> 








■ll 




1^ 




















o 


o 


o 


o 


o 


O 


o 


o 


o 


o 


O O 


O 


o 


o 



















n 


in 


o 


m 


n 


in 


o 


m 


o 


;c R 


in 


n 


in 




























r^ 












t^ 














VO 


o 




on 








m 




\o 








i^ 


rn 














w 


o 


M 




(N 


<n 


to 


■* 


m 




























o 


o 


O 


o 


O 


o 


O 


O 


o 


o 


o o 


O 


o 


o 




















o 


r^ 




o 


r^ 


en 


n 


o 


rn O 


VO 


m 




















OO 










^ 




































































M 


o 


M 


Ol 




^ 








VU 


























o 


o 


O 


o 


o 


o 


O 


O 


o 


o 


o o 


o 


O 
















o 




M 


fO 


■* 




vO 


r- 


00 


Ov 


o 


M M 


rn 


t 


in 


VO 


r- 


00 o. 


o 


M 


N 









































INDEXING ANGLES 



191 



i 


>o \o 


t^ 


00 


Ov 




CO 


Ov 


w <N CO 'd- 10 VO 


t^ CO 











(N to 


to to to to to to to 


to 


to 'T 


T 't "T '^ ^ ^ 


^ T 




s^ 


"^ 


^ 00 <N 


VO M lO 0> to r- HI 


"wo" 


Ov to 


t^ M 10 't 00 

>0 r- t^ 00 00 CO 


(N VO 


c- 




M 


M M 


f-1 to to to ^ ■* >o 




VO VO 





M to 




r^ 


Ov M 


to lo t- ov M to 10 


t^ 


0> H 


CO >o t^ Oi M CO 




■* 




10 




XT, VO 


VO VO VO VO t^ r^ t- 




t- 00 


00 00 00 00 Ov Ov 


s 




6 d 


d 


d 


d d 


d d d d d d d 


d 


d d 


6 6 6 6 6 6 


d d 




M "^ 


>o 


t^ 


to 


VO Ov M •* r^ <N 


VO 


CO H 


to -o Ov <N rt r- 








Tj- 




!>. 00 


00 (N r/, ,-j. VO t^ 




Ov H 


<N to ■* VO t^ 00 








r^ 





H to 


VO 00 M Tl- t- 00 






1>- Ov M to 10 t^ 




■* 


>r> U-1 


10 




VO VO 


vO vO t^ t-- t^ t^ r^ 


CO 


c» 00 


CO CO Ov Ov Ov 




d d 


d 


d 


d d 


6 6 6 6 6 6 6 


d 


d d 


6 6 6 6 6 6 




't r- 


Oi 


P4 


5f: 

t^ Ov 


Ov <N •* f- <N lO 


r^ 


IN 


10 CO 




f^ 


00 




VO 


t t^ '^ t- 


S 


r- 


to VO 
VO r^ 




•* 


10 


VO 


VO 


VO v5 


rl tS[ t^ t^ (5 00 00 


00 


0> Ov 


Ov 






d d 


d 


_o_ 


d d 


d d 6 6 6 6 6 


d 


d d 


d d 






00 w 


10 


Ov 


to t^ 


M lo 0. to t^ ■* 


00 


<N 








•:)- 


00 




t^ M 


VO •* OV to CO <N 


VO 










ro 


to 


c» 


to 


10 00 t^ vc t^ 

r^ r^ 00 CO CO 00 0> 




VO r^ 






"+ 


VO VO 








t^ r- 


o> 


Ov Ov 








d d 


d 


d 


d d 


6 6 6 6 6 6 6 


_d_ 


d d 











to 


Ov 


VO <N 


0> VO (N CO '^t M 1-- 


to 










M vO 




t^ 


to 


^ vO 1-1 r^ to CO 


^ 











■:*• 


o> 




-t VO 


Ov c, ^ t^ Ov « Tl- 


t^ 








rO 


VD 





r^ 


t^ t^ 


t^ 00 00 00 00 Ov a. 


Ov 










d d 


d 


d 


d d 


6 6 6 6 6 6 6 


d_ 










r- r^ 


t^ 


00 


CO 00 


CO r^ Ov C 










o> 


VO 


<o 


I^ .^t M OD 10 to 










f^ 


r~ 






00 M 


to 0> M -+ t^ 










to 


VO t^ 


t^ 


r^ 


t^ 00 


00 00 00 Ov 0> Ov 












d d 


d 


d 


d d 


6 6 6 6 6 6 






^ > 


\ 




10 00 


H 


.rf 


r- 


to VO 








r^ r- 


00 


00 


00 


Ov 






>-Y 


X 


rO 


>/-; 00 




Tt 


r^ 

00 








\ 


ro 


r^ r^ 


00 


00 


s 






« r\ 


\ 




d d 


d 


d 


d d 


d d 






J--C---, 


) 




ly-> t-^ 





c^ 


10 i^ 




~ 




1 








to 


10 r^ 








\ 


/ 


<0 


00 00 

d d 


d 


a 

d 


d d 








V 


y 




M 





10 






























Oi 


"S 




VO 














N 


00 00 

d d 


d 


Ov 

d 
















0^ 
















\n to 


















" 


0. VD 

d d 


















H 










•oper 
r all 
tion. 

sec. 

the 






'1 




< 














-0 ■- 




I-) 










a ° S M -S 






E 3 




Ph 
X 








(2^ 


lllil 








Q 








h-) 








^ 




2 










<3 


culations when obta 
grees, minutes or sec 
e will readily show its 
one of 31 deg., 17 nn 
ds = 112,631. One 
to seconds = 32,400. 






*3 M-i 

5 . 













^ 























VO 

to 


" 8 












HH 


"d-S &•== §1 




II 


^ > 














s many 
either in 
An exar 
; indexed 
gle to se 
hich redu 


5 1 


d - 












s 




















. pq 


Ji a -B ,D S ^ 
















S 


The tab 
dex for a 
ree collec 
The angl 
educing 1 
ank = 9 c 






We. find 
holes on t 
places. 














.S5 rt S 









192 



MILLING AND MILLING CUTTERS 



MILLING CUTTER, REAMER AND TAP FLUTES 

The following tables give the number of teeth or flutes suitable 
for milling in various types of cutters, reamers, taps, etc., and also 
show the forms of fluting cutters used. 



End Mills 



Straight Teeth 




Spiral Teeth 




Dia. Mill 


No. Teeth 


Dia. Mill 


No. Teeth 


A to t\ 

f to I 

I J to if 


6 

8 

10 

12 

14 


\ to h 

T^eto if 

I to li 

if to I i 


8 
10 

12 
14 



Shell End Mills-, Straight 
Teeth 


OR Spiral 


Inserted Tooth Cutters, P. & W. Form 


Dia. Mifl 


No. Teeth 


Dia. Cutter 


No. Blades 






4 


10 






5 


12 






6 


16 






7 


18 


il to I^ 


16 


8 


20 


if to 2x^^ 


18 


10 


24 


2|tO 3 


20 


12 


28 



Metal Slitting Cutters 



Thickness 


Pitch 


Thickness 


Pitch 


i^ 


h 


♦ 


Pr 




\ 


^ 


¥ 


■jV 


■s% 


i 


t 


i 


A 







Screw Slotting Cutters 



Cutters thinner than 3V cut ^ pitch, 
Cutters -^ to ^ thick cut -^s pitch. 
Cutters over ^^ thick cut 3^ pitch. 



PLAIN MILLING CUTTERS 



193 



Plain Milling Cutters 


Fluting Cutters 


Dia. of Cutter 


No. of Teeth 


J 




2 to 2! 


18 


\ ■ 


3 to 3I 

4 to 5 
5i to 6 
6ito 8f 
9 to 9I . 
9J to 10 

io| to 1 1 


20 
22 
24 
26 
28 

30 
32 




/ 


40° to 48° 








Form of Cutter for Milling 
Teeth in Plain Milling 
Cutters. 



Plain cutters of f-inch face and over are generally made with 
spiral teeth. The 12-degree angle on side of fluting cutter gives 
ample clearance for cutting spiral grooves with the 12-degree face 
set on the center line of the work. 



Side or Straddle Mills 








Dia. of Cutter 


No. of Teeth 


- 


aX^ 


2 


16 


\ 


2^ 

2f to 3i 

34 to 4i 

5 to5f 

6 to6| 

7 to7| 

8 to8f 


20 
24 
26 
28 

30 
32 
34 












Angular Cutter for MilUng 
Teeth in Straddle Milling 
Cutters. 



For milling teeth on periphery of straddle mills use angular cutter 
with 60 degree angle at A; for milling teeth on sides of cutters use 
70°, 75° or 80° cutter according to number of teeth in cutter to be 
milled. 



194 



MILLING AND MILLING CUTTERS 



Corner Rounding Cutters 



Fluting Cutters 





2i to 3i 
3ito4 



Angular Cutter for Milling 
Teeth in Corner Round- 
ing, Concave and Convex 
Cutters. 



Angular Cutters 










Dia. of Cutter 


No. of Teeth 


1 


fv 


3 


l8 
20 
22 


B 


/ 


\ 




Double Angle Cutters 




Dia. of Cutter 


No. of Teeth 




2* to 3 


22 





Cutters for Spiral Mill; 



Dia. of Cutters 



2* 

3 




Cutter for Milling Teeth in 
Angular Cutters, Double 
Angle Cutters and Cut- 
ters for Spiral Mills. To 
cut Teeth on side A of 
this Cutter use 6o° Cutter. 
To cut side B use 7o°-75^ 
Cutter. 



SCREW MACHINE TAPS 



195 



Hand Taps 


Tap Fluting Cutter 


Dia. of Tap 


No. Flutes 


( 

With 

3 Flutes in 

4 Flutes in 

5 Flutes in 

6 Flutes in 

7 Flutes in 

8 Flutes in 

With 

3 Flutes in 

4 Flutes in 

5 Flutes in 

6 Flutes in 

7 Flutes in 

8 Flutes in 

In milHng 
cutter the c 
the tap. 








^toif 

l| to 2f 

3 to 4 
3 to 4 mm. 
5 to 44 mm. 


4 
6 
8 

3 

4 
6 


^ 


^--B— 


J. 




46 to 50 mm. 








Taps 




Machine Screw 




2 






No. Flutes 




Dia. of Tap 


X_?. 




No. I to 7 
No. 8 to 30 


3 
4 


Tap, 
Tap, 
Tap, 
Tap, 
Tap, 
Tap, 

Tap, 
Tap, 
Tap, 
Tap, 
Tap, 
Tap, 

taps 
atter r 


B = 1 Dia. 
B = J Dia. 
B = If Dia. 
B = H Dia. 
B = 3% Dia. 
B = 1 Dia. 

E = 3^ Dia. 
E = 1 Dia. 
E = If Dia. 
E = 11 Dia. 
E = i^ Dia. 
E = -h Dia. 

w^ith the c 




Tapper Taps 




Dia. of Tap 


No. Flutes 




itoif 

if to 2 
2i 


4 

5 
6 


Tap 
Tap 
Tap 


Machine or Nut 


Taps 


Tap 
Tap 


Dia. of Tap 


No. Flutes 


Tap 


A to f\ 

f t0 2l 
2|t0 3 

33 to 4 


4 
5 
6 

7 


Tap 
Tap 
Tap 
Tap 


Screw Machine Taps 


Tap 
Tap 


Dia. of Tap 


No. Flutes 


onvex 


i toii 

lAt0 2 


4 
6 


nus 


t be centra 


with 



196 



MILLING AND MILLING CUTTERS 



Taper Pipe Taps 


Tap Fluting Cutters 


Dia. of Tap 


No. of Flutes 




ito 1 


4 


/-^ /K 


1 


4 or 5 




( 


1 \ \ 


I to ij 


5 








\Y\ 




2 


7 












2i 


8 
9 












3 


.__. 






3^ to 4 


II 






/ 








Straight Pipe Taps 


UJ 




Dia. of Tap 


No. of Flutes 








B Ta 


ito i 


4 




1 to I^ 


5 




I^ 


6 




2 


7 


Cutter A is a regular tap fluting cutter 


2i 


8 


that may be used if preferred for fluting 


3 


9 


any kind of tap in place of convex 


3i 


ID 


cutter B. 



Pipe Hobs 



Dia. Hob 


No. 
Flutes 


Dia. Hob 


No. 
Flutes 


Dia. Hob 


No. 
Flutes 


Hob Fluting 
Cutter 


Jtoi 


6 


I 


12 


3 


28 


A 


i 


8 


li to I^ 


16 


34 


34 


/ \ 


\ 


9 


2 


20 


4 


36 


L.A 


* 


10 


2i 


24 


4i 


46 








Sellers Hobs 


Hob Taps 




Dia. Hobs 


No. 
Flutes 


Dia. Hob 


No. 
Flutes 


Dia. Hob 


No. 
Flutes 




■ to yV 


6 


if to 2\ 


12 


\ to \ 


6 


1 




^ to ^ 


8 


2% to 2| 


14 


A to 11 


8 


In fluting 


H to li 


10 


3 to 4 


16 


1 toii 

I f to 2 


ID 
12 


hobs leave 
land -^-^ inch 
wide on top. 



CUTTERS FOR FLUTING REAMERS 

Shell Reamers 



197 









r-" 




1 

;2 


Dia. of Reamer 


"o 


Dia. of Reamer 


'o 


Dia. of Reamer 


"o 




1 









6 


itof 


6 


|1 to li 


10 


23% to 2f 


14 


Mtof 


8 


iH to 2i 


12 


2f f to 4 


16 



Cutters for Fluting Reamers 



Dia. of 


R = Radius 


Dia. of 


R = Radius 




Reamer 


of Comer 


Reamer 


of Corner 


\ ^ 


* to j\ 





I J toii 


tV 




ito i 


^V 


It's to 2i- 


.\ 


/ \ \^ 


ito ^ 


3^ 


2T\t0 3 


A 








f to I 


eV 














A = Am't Cut- 




A = Am't Cut 




Dia. of 


ting Edge is 


Dia. of 


ting Edge is 
Ahead of 








Reamer 


Ahead of 


Reamer 










Center 




Center 








i 


.Oil 


l| 


.066 




i 


.016 


If 


.076 








1 


.022 
.027 


2 
2i 


.087 
.098 




u 


vv 




4 


■<^33 


2* 


.109 


'A 


^7<^ 


i 


.038 


2f 


.120 


/w \ 


I 


.044 


3 


•131 


1 \\ \ 


li 


.055 






( \\ 










V3/ 



The type of cutter shown may be used for all classes of reamers 
except rose reamers. 



MILLING AND MILLING CUTTERS 

Rose Chucking Reamers 



•X. 



Use 75 Angular 
Cutter for End. 



Use 80 Angular 
'Cutter for Flutes 



Depth of Groove = H to % Dia. 





"d 






-d 






(3 






a 






w 






W 




Dia. of Reamer 


•oi2 
6U 


No. of 
Flutes 


Dia. of Reamer 




No. of 

Flutes 




Z 






^ 




ito i 


6 


3 


if to 2 


12 


6 


t to I 


8 


4 


2i to 2 J 


14 


7 


ijtoij 


lO 


5 


2f to3 


i6 


8 



Taper Reamers 



Morse Taper 


B. & S. Taper 


Jarno Taper 




<*H m 




M-1 CO 




V*, lA 














No. of Taper 


6.5 


No. of Taper 


6 3 


No. of Taper 


6 3 




^t. 




;^t^ 




Zu. 


o to I 


6 


I to 5 


6 


2 


4 


2 to 4 


8 


6 to ID 


8 


3 to 4 


6 


5 


ID 


II to 12 


10 


5 to 10 


8 


6 


14 


13 


12 


II to 15 


10 


7 


i6 


14 to 16 


14 


16 to 18 


12 






16 to 18 


16 


19 to 20 


14 



Taper Pin Reamers 


Locomotive Taper Reamers 


No. of Reamer 


No. of 
Flutes 


Dia. of Reamer 


No. of Flutes 


OOOO to 00 

to 7 

8 to 10 

II to 14 


4 

6 

8 

10 


i to i 
i^toii 

lA to if 

ill to 2 


6 

8 

10 

12 



HALF-ROUND KEYWAY 



199 



Center Reamers 
diameter of straddle mill for fluting (3 flutes; 





Outside 




Outside 


Size of Reamer 


Dia. of 


Size of Reamer 


Dia. of 




Cutter 




Cutter 


Y cut 


2j 


r cut 


3l 


r cut 


2f 


r cut 


3f 


r cut 


3 


i'' cut 


4 


f'' cut 


3i 







CUTTER KEYWAYS 




Square Keyway 



Dia. Hole, A 
Width Key, W 

Depth, D 

Radius, R . . . 



8 176 
3 
32 

6^ 
.020 



.030 



* 
•035 



32 
.040 



ItWI 
1 



.050 



iti 



32 
.060 



I 



.060 



16 

t\ 
.060 




Half- Round Keyway 



Dia. Hole, A. 


l-f 


H-H 


FlT^ 


li-IlV 


1^-2 


2tV2tV 


2^-3 


Width, W.... 


i 


^ 


i 


t\ 


1 


^^ 


i 


Depth, D 


tV 


^^^ 


i 


3^ 


1^ 


.V 


i 



200 



STANDARD T-SLOT CUTTERS 




Width of Slot 


Diameter of 


Width of Slot 


Depth 


Extreme Limit 


A 


Neck of Cutter 


B 


D 


Inches 


Inches 


Inches 


Inches 


Inches 


I 


i2 


h 


A 


A 


A 




1 


fa 




f 


32 




sV 


T^ 


tV 


1 


— 1- 


3^2 


■^-g 


h 


tV 


if 




A 


f 


H 


lA , 


f 




li 


1X^6 


-| 


I 


X 


If 


I 1 


-* 


ItV 


I 


ft 




If 


lA 



These cutters are made /a i^ch larger in diameter and ^\ inch 
greater in thickness than the figures given, to allow for sharpening. 



Largest Squares that can be Milled on Round Stock 



Diam. of 


Decimal g 


ze of 


Nearest 


Diam. of 


Decimal 
Equiva- 
lent 


Size of 


Nearest 


Stock 


lent ^ 


[juare 


Fraction 


Stock 


Square 


Fraction 


i 


.125 


088 


A- 


l/lT 


1-5625 


1-105 


i.V- 


l\ 


.1875 


133 


i + 


If 


1.625 


1. 149 


13*^- 


\ 


.250 


177 


•fi- 


't* 


1.6875 


1. 193 


It\ + 


fe 


•3125 


221 


i^ + 


If 


1-750 


1-237 


iM + 


1 


.375 


265 


il 


lif 


1. 8125 


1.282 


l/^ 


<^ 


.4375 


309 


I!~ 


If 


1-875 


1.326 


Ifi- 


i 


.500 


354 


^1 _ 

64 


lit 


1-9375 


1-370 


If - 


T% 


•5625 


398 


11 + 


2 


2.000 


I.414 


lit + 


« 


.625 


442 


tV + 


2tV 


2.0625 


1-458 


iff + 


ii 


.6875 


486 


fi + 


2f 


2.125 


1.502 


i^ + 


f 


•750 


530 




2A 


2.1875 


1-547 


Iff 


Tt 


.8125 


574 


f ¥ ~ 


2i 


2.250 


1-591 


iff- 




•875 


619 


1 - 


St'V 


2.3125 


1-635 


iff- 


xf 


•9375 


663 


M + 


2f 


2-375 


1-679 


iff + 


I 


1. 000 


707 


M + 


2tV 


2.4375 


1-723 


i|l + 


ItV 


1.0625 . 


755 


1 + 


2i 


2.500 


1.768 


ik + 


li 


1. 125 


795 


f i — 


2t^ 


2.5625 


1.813 


Ik 


It\ 


1-1875 


840 


II — 


2f 


2.625 


1-856 


if-- 


li 


1.250 


884 


II — 


2H 


2.6S75 


1.900 


if^- 


IT^^ 


1.3125 


928 


f f + 


2f 


2.750 


1.944 


iH + 


If 


1-375 


972 


fi- + 


2H 


2.8125 


1.989 


iff + 


itV 


1.4375 I 


016 


i^V + 


2f 


2.875 


2.033 


2h + 


I^ 


1.500 I 


061 


ItV - 


2H 

3 


2.9375 
3.000 


2.077 
2.121 


2i^- 


SideofLar 


gest Square = I 


Ma.ofS 


tockx.707 


2f - 



DISTANCE ON CIRCUMFERENCE 



20I 



Table of Divisions Corresponding to Given Circumferential 
Distances 

This table gives approximate number of divisions and distances 
apart on circumference, corresponding to a known diameter of work. 
It is useful in milling-machine work in cutting mills, saws, ratchets, 
etc. 





Distance on Circumference 


Dia. of 




Work 


































3^" 


i^g" 


r 


^Y 


X" 


i%" 


1" 


iV 


i" 


1%" 


r 


ir 


r 


i" 


ir 


f 


25 


12 


6 




























31 


16 


8 


























1 


38 


19 


9 


6 
























1^ 


44 


22 


II 


7 


5 






















^ 


50 


25 


13 


8 


6 






















1 


63 


31 


16 


10 


8 


6 




















f 


75 


38 


19 


13 


9 


8 


6 


















1 


88 


44 


22 


15 


II 


9 


7 


6 
















I 


100 


50 


25 


17 


13 


10 


8 


7 


6 














i 


126 


63 


31 


21 


16 


13 


10 


9 


8 


7 


6 










J 


150 


75 


3S 


25 


19 


15 


13 


II 


10 


8 


7 










4 


176 


88 


44 


29 


22 


18 


15 


13 


II 


ID 


9 


8 


7 


6 




2 


200 


100 


50 


34 


25 


20 


17 


14 


12 


II 


10 


9 


8 


7 


6 


i 


226 


113 


56 


38 


28 


23 


19 


16 


14 


13 


II 


ID 


9 


8 


7 


J 


251 


125 


63 


42 


31 


25 


21 


18 


16 


14 


12 


II 


ID 


9 


8 


1 


277 


138 


69 


46 


35 


28 


23 


20 


17 


15 


14 


13 


12 


10 


9 


3 


302 


151 


75 


50 


38 


30 


25 


22 


19 


17 


J5 


14 


13 


II 


9 


i 


327 


163 


82 


54 


41 


33 


27 


23 


20 


18 


16 


15 


14 


12 


10 


^ 


352 


176 


88 


59 


44 


35 


30 


25 


22 


20 


18 


16 


15 


13 


II 


f 


378 


189 


94 


.63 


47 


38 


31 


27 


24 


21 


19 


17 


16 


14 


12 


4 


402 


201 


100 


67 


50 


40 


34 


29 


25 


22 


20 


18 


17 


IS 


13 


i 


428 


214 


107 


71 


53 


43 


^^0 


31 


27 


24 


21 


19 


18 


15 


13 


i 


454 


227 


114 


76 


57 


45 


38 


32 


28 


25 


23 


21 


19 


16 


14 


f 


478 


239 


119 


79 


60 


48 


40 


34 


30 


27 


24 


22 


20 


17 


15 


5 


503 


252 


126 


84 


63 


50 


42 


36 


31 


28 


25 


23 


21 


18 


16 


i 


528 


264 


132 


88 


66 


53 


44 


38 


33 


29 


26 


24 


22 


19 


16 


1 


554 


277 


138 


92 


69 


55 


46 


40 


35 


31 


27 


25 


23 


20 


17 


f 


579 


289 


145 


96 


73 


58 


48 


41 


36 


32 


28 


26 


24 


21 


18 


6 


604 


302 


151 


lOI 


76 


61 


50 


44 


38 


34 


30 


27 


25 


22 


19 



For example: A straddle mill, say, 5 inches in diameter, is to be 
cut with teeth yV apart. Without a table of this kind the workman 
will have to go to the trouble "of multiplying the diameter by 3.14^6 
and then divide by j\ to find the number of teeth to set up for. In 
the table, under j\ and opposite 5, he can find at once the number 
of divisions, as 36. Where the table shows an odd number of teeth, 
one more or less can, of course, be taken if it is important to have 
even number of teeth. 



202 MILLING AND MILLING CUTTERS 




MILLING SIDE TEETH IN MILLING CUTTERS 

The table gives the angle at which to set the dividing head of a 
miller when milling the side teeth in milhng cutters. 



Milling Side Teeth in Milling Cutters. 
DiviorNG Head 



Angle to set 









Angle of 


Cutter Used 








No. of 


















Teeth 


45° 


50° 


60° 


65° 


70° 


75° 


80° 


85° 


6 








36° 08' 


50° 55 


62° 21 


57° 08 


81° 17 




7 






43° 36' 


^X ^K 


62° so 


70° 22 


72° 13 


83° 42 




8 




32° 57' 


54° 44 


6i' 30 


68° 39 


74° 04 


77 13 


84° 52 




9 


32" 58 


45° is' 


61° 01' 


66° 58' 


72° 13 


77° 00 


81° 29 


85° 47 




lO 


43° 24 


52° 26' 


65° 12' 


70° 12' 


74 40 


78° 46 


82° 38 


86° 14 




12 


54° 44 


61° 02' 


70° 33 


74° 23' 


77° 52 


81° 06 


84° 09 


87° 06 




14 


61° 12 


66° 10' 


73° 51' 


77° oi' 


79° 54 


82° 35 


85° 08 


87° 35 




i6 


65° 32 


69° 40' 


76° 10' 


78° 52' 


81° 20 


83° 37 


8S°49 


87° 55 




i8 


68" ,SQ 


72° 13' 


77° 52' 


80° 13' 


82° 23 


84° 21 


86° 19 


88° IG 




20 


71 03 


74 11' 


79 II 


81° 17' 


83° 13 


85° 00 


86° 43 


88° 22 




22 


72° 55 


75° 44' 


80° 14' 


82° 08' 


83 52 


85° 29 


87° 02 


88° 31 




24 


74° 28 


77° 00' 


81° 06' 


82° 49' 


84° 24 


8S°53 


° 87° 18 


88° 39 




26 


75° 44 


78° 04' 


81° 49' 


83° 33' 


84° 51 


86° 12 


87° 30 


88° 45 




28 


76° 49 


78° 58' 


82° 26' 


83° 53' 


85° 14 


86° 29 


87° 42 


88° SI 




30 


77° 44 


79° 43' 


82° 57' 


84° 18' 


85° 34 


86° 44 


87 51 


88° 56 




32 


78° 32 


80° 23' 


83° 24' 


84° 40' 


8s°5i 


86° 56 


87° 59 


89° 00 




34 


7Q° 14 


80° =59' 


83° 48' 


85° 00' 


86° 06 


87° 08 


88° 07 


89° 04 




^6 


79° 51 


81° 29' 


84° 09' 


8s°i7' 


86° 19 


87° 17 


88° 13 


89° 07 




^8 


80° 24 


81° 58' 


84° 29' 


8s° 32' 


86° 31 


87° 26 


88° 18 


89° 09 




40 


80° S3 


82° 22' 


84° 45' 


83° 46' 


86° 42 


87° 34 


88° 24 


89° 12 




42 


81° 20 


82° 44' 


85° 00' 


8s° 58' 


86°. 51 


87° 41 


88° 29 


. 89° 14' 



The table shows the angle to the nearest minute, but as an ordinary- 
dividing head is not graduated to read in minutes, the nearest quarter 
degree is taken. 



SPEEDS FOR COLD SAWS 



203 



CUTTING SPEEDS FOR COLD SAW CUTTING-OFF 
MACHINES 

The table on page 204 shows the practice of the Brown & Sharpe 
Mfg. Co. The semi-high speed still is used for soft steel but high 
speed is recommended for cutting tool steel. A good lard cutting oil 
is preferred though it can be dark colored and more impure than for 
screw machines. 

The experience of this company has led to the adoption of the saw 
tooth shown herewith. This allows a slower speed and coarser feed 
than finer teeth, and cuts stock more easily and quickly. 



Space 




-^"r*^A 





Screw Diam. ' Thickness 
16"to 18" 5/32" 

22" 3/,j" 

24" V32" 



Section of Cut 



Newton Machine Tool Works recommend a high speed and light 
feed for steel low in carbon and manganese to keep the chip thin as 
possible. Up to 35-point carbon use 6b to 65 feet per minute for 
sohd blades. From 35 to 50-point carbon, 55 to 60 feet per minute 
and less feed. Above 50-point carbon use inserted tooth saws. With 
inserted tooth saws speeds can be from 50 to 80 feet per minute 
on 50 to 70-point carbon, but only on heavy, rigid machines. For 
cutting sprues in steel foundries a solid tooth saw with a speed 
of 55 feet per minute and a feed of J to f inch per minute is recom- 
mended. "* 

The work should be flooded at all times with any good cutting 
compound which does not rust. A good mixture is: whale oil, 9 
quarts; pure lard oil, 2 gallons; sal soda, 15 pounds; and 40 gallons 
of water. 

The Tindel-Morris Co. give f inch per minute as a safe feed for 
steel bars of 45-point carbon from 2 to 10 inches in diameter. The 
speed of inserted tooth saws is given as 25 to 30 feet per minute, as 
this, with a coarse feed, gives good results. This is with f inch spacing 
between teeth. Liberal power is needed — a 36-inch saw requiring 
from 10 to 15 horsepower. 



204 



MILLING AND MILLING CUTTERS 



1 

i 


303T^ 3U0 so ?^3 

o} -uij^ -xoidd'^ 


CO <N ir> c> fOOO PO t^ 10 Tf Tf 


•Uipi[ J9d 'MBS 

JO saoT;niOA3^ 


rOrocoroM H m moOoO loiovo 


'MBS JO P^3J 


i^ IJOCO vo fOOO MD vo OO * 
uo lo 10 C-) M o\ r-~\o vo PO c^ M 

<N(N<NO)C^MMHMHMMM 

odddddddddddd 


•mfl J9d -ij 'AVBS 
JO p93ds Sui^^nj 


0000000000000 


MBS UI q599X 

JO i9quin^ 


2II2 1 2 2 2 §§ H§ § 


1 

1 


0; -uijy; •xojddy 


fO '^O r- M CO 1000 M 10 10 


•nTI\[ J9d MBS 

JO suopniOA9^ 


t^ !>. ^^ ^°9 oqcooOMMMMM 

mD 'j- ^ ^ rj- oi (N M M M 




•uipv I9d S9qDUI 
'MBS JO P33jl 


looo T^c^rto rooNO 000 

lOOO rtOCOO rOOOO iO<N 

ddddddddddddd 


•mp\[ J9d •; J 'MBS 
JO p99ds SuTiin3 


0000000000000 


MBS «! qi33X 

JO J9quin^ 


coooooooooooooco 
00000000'N<N<NO)(N 




1 

1 
1- 

>> 

1 


9D3i(j ano 50 ^"3 
o; ■u;i'\[ -xojddy 


H W H H <N OJ 


•UIJAI J9d MBS 

JO saopnpA9^ 


On On 0\ 0\0 vOOOOO <^C>q\ 

HMHMddddo6o6i>.t-^t^ 


•mj;^ J9d S9qDni 

■ MUSJOP99J 


coO csoo Tj-Mr>.r^ 
00 ro 10 rj-oo 10 M to 
00 00 t^ l>.>0 vO u-jLoiort-'^POro 

ddddddddddddd 


•mjAI J9d -5 J 'MBS 
JO p99ds Supino 


0000000000000 

lOtoiOlOlOlOlOlOlOlOlOlOl-O 


MBS m qi99X 
JO J9quinjsj 


r-- r^ t^ rs. t^ <r^ r>. r^co 00 00 00 00 


MBg JO ja^aoi-BiQ; 


vOOOOOOoOoOOO <N (N -^^T^ 

MIHMMMIHMM(N<N(N<NCN 




JPOJS JO J9;9raBIQ 


r-l|M rH!N rt|N -<|N w|M rtllN 

(N <N CO CO '^ '^t- to 100 *0 ^^ t^OO 



TURNING AND BORING 

The accompanying table is a ready means of figuring machine time 
on turned, bored or faced work. 

The ordinary method employed is to ascertain the number of feet 
in the circumference of the piece by multiplying the diameter in 
inches by 3.1416 and dividing by 12. The next step consists of 
dividing the length by the feed used, which gives the entire number of 
revolutions the piece must make. 

Constants for Cutting Time, in Minutes 



Feed m 
Inches 


Cutting Speed 


Two Cuts at 


15 Feet 


' 18 Feet 


20 Feet 


25 Feet 


30 Feet 


35 Feet 


40 Feet 


1-64 1-32 


1.676 


1.396 


1-257 


1.005 


0.8378 


0.7181 


0.6281 


1-32 1-16 


0.8378 


0.6981 


0.6283 


0.5027 


0.4189 


0.3590 


0.3141 


1-16 I- 8 


0.4189 


0.3491 


0.3142 


0.2513 


0.2094 


0.1795 


0.1570 


.1-8 1-4 


0.2094 


0.1745 


0.1571 


0.1257 


0.1047 


0.0898 


0.078s 


One Cut at 
















1-64 


1. 117 


0.9308 


0.8378 


0.6702 


0.5585 


0.4787 


0.4189 


1-32 


0.5585 


0.4654 


0.4189 


0.3351 


0.2793 


0.2394 


0.2094 


1-16 


0.2792 


0.2327 


0.2094 


0.1676 


0.1396 


0.1197 


0.1047 


I- 8 


0.1396 


0.1164 


0.1047 


0.0838 


0.0698 


0.0598 


0.0524 


I- 4 


0.0698 


0.0582 


0.0524 


0.0419 


0.0349 


0.0299 


0.0262 


Two Cuts at 


45 Feet 


50 Feet 


60 Feet 


70 Feet 


80 Feet 


90 Feet 


100 Feet 


1-64 1-32 


0.5581 


0.5027 


0.4189 


0.3590 


0.3142 


0.2793 


0.2513 


1-32 1-16 


0.2793 


0.2513 


0.2094 


0.1795 


0.1571 


0.1396 


0.1257 


1-16 I- 8 


0.1396 


0.1257 


0.1047 


0.0898 


0.0785 


0.0698 


0.0628 


1-8 1-4 


0.0698 


0.0683 


0.0524 


0.0449 


0.0393 


0.0349 


0.0314 


One Cut at 
















1-64 


0.3723 


0.3351 


0.2793 


0.2394 


0.2094 


0.1852 


0.1676 


1-32 


0.1862 


0.1676 


0.1396 


0.1197 


0.1047 


0.0931 


0.0838 


1-16 


0.0931 


0.0838 


o.o6g8 


0.0598 


0.0524 


0.0465 


0.0419 


I- 8 


0.0465 


0.0419 


0.0349 


0.0299 


0.0262 


0.0233 


0.0209 


1- 4 


0.0233 


0.0209 


0.0175 


0.0150 


0.0131 


0.0116 


o.oios 



Having the circumference in feet and the number of revolutions, 
it is necessary to multiply them to find the entire number of feet 
traveled. Dividing this result by the speed of cut in feet per minute 
will give the actual cutting time in minutes. 

The figuring is not comphcated in any way, but it has the disad- 
vantage of taking too much time. It can be resolved into the follow- 
ing formula: 

205 



2o6 TURNING AND BORING 

Diameter X 3-Ui6 X length in inches ^ ^.^^ .^ ^,^^^^^^^ 
12 X speed X feed in inches 

The known factors in the case can be resolved into a constant 
which is directly dependent on the feed and speed; hence, a table 
covering a wide range of speeds and feeds is necessary for their proper 
use. 

One part of the table gives constants for two cuts at e^-inch and 
/o-inch feed, up to |-inch and i-inch feed, at any speed from 15 feet 
to 100 feet per minute. The rest of the table gives constants for 
one cut at g^-inch up to and including J-inch feed, also at any speed 
from 15 feet to 100 feet per minute. 

A typical computation is as follows : 

A piece 4 inches in diameter, 10 inches long, is turned with two cuts 
at xViiich and gVinch feed, each with a cutting speed of 20 feet per 
minute. Diameter X length in inches X constant = time in min- 
utes. 4 X 10 X 0.6283 = 26 minutes. 

If, for the purpose of accuracy it is thought advisable, in connec- 
tion with these two cuts, to run another cut over, the constant 0.6283 
is added to a constant for the third feed used. If this feed is g^^-inch, 
then we have 0.6283 + 0-8378 = 1.4661, the constant for three cuts, 
one of xViiich, one of j^^-inch, and one of g^^j-inch feed. 

Table Has Wide Application 

There is hardly a combination of feeds and speeds that it is not 
possible to secure by inspection from the table. By interpolation 
an added number can be secured. 

The table can be adapted, on account of its wide range, to the 
kno^vn individual performance of any lathe or boring mill in the shop. 
No slide rule or any special operations are necessary to secure the 
desired results, merely a knowledge of multiplication. 

For flange facing it is possible to use the table with the same ease 
as for boring and turning by figuring on the main diameter. 

Rotary Cutting Speed 

An easy method of calculating the cutting speed of a lathe tool 
or milling cutter is to divide the number of revolutions by 4 and 
multiply by the diameter in inches. This gives the cutting speed 
in feet per minute. Dividing 3.1416 by 12 gives .262 and .25 is very 
close after allowing for belt slip. 

Let D = diam. of work, cutter or boring bar. 
N = revolutions per minute. 
C = cutting speed in feet per minute.. 

4 D N 

Lathe Tool Tests 

In testing steels for lathe and similar tools it has become custo- 
mary to use standard material, speeds, feeds and depth of cut. In 
some cases tools are run until they break down, in others they are 



CUTTING LUBRICANTS 207 

passed if they stand up for a specified time. A 20-point carbon steel 
is often selected and cuts I inch deep wdth jV to | inch feed at cut- 
ting speeds of from 60 to 90 feet per minute. 

The U. S. Navy Department specifies that a |-inch lathe tool 
shall stand up for 20 minutes with a yVi^ch cut and j-^j-inch feed at 
60 feet per minute without regrinding; the material must be at least 
80,000-lb. , tensile, and 50,000-lb. elastic limit -with a 25 per cent, 
elongation in 2 inches. The steel is annealed before the test. 

Cutting Lubricants 

Cast iron is usually worked dry, but when hard cast-iron gears are 
to be cut, as ^^^th three cutters, the first cut through will work better 
with strong soda water. It makes an objectionable mess, but the 
work will be done faster and the cutters keep sharper longer than 
with the dry process of cutting. 

Brass and babbitt are usually cut dry, but to hand-ream brass and 
babbitt is sometimes difficult if the reamer is a httle dull. Kerosene 
and turpentine are used with good results. Cast iron can be hand- 
reamed easily with tallow and graphite, mixed, and the hole will 
be kept just the size of the reamer. Copper can be worked well v.dth 
lard-oil and turpentine mixed. 

In boring babbitt bushings and rod boxes in a lathe or boring mill, 
it is very difficult to work the material dry as the chips have a great 
tendency to roll around the tool and into a hard ball, tearing the 
metal and making a rough ragged hole. In this case kerosene and 
lard-oil mixed will work well. 

Cheap oil is sometimes used as a lubricant for cutting, but soap 
water or soda water is better for iron and steel shafting and with a 
sharp tool and light finish cut the work will be smooth enough to 
polish wthout filing. 

Rawhide is a very peculiar substance to work, and to drill it with 
a twist drill is a tedious job, as the flutes wiW clog and stick if run dry. 
A cake of soap held against the drill will prevent all trouble and 
sticking of drills. It is bad practice to use oil on rawhide as it injures 
the fiber and loosens the glue. Drills should be run at very high 
speed in rawhide to work well. 

Turpentine is good in some cases where fitting is done, such as 
scraping lay-out plates, or face plates. Oil will form a coating so 
that marks cannot be seen plainly, but turpentine will prove bene- 
ficial on this kind of work if used freely. The marks can be seen 
plainly, and the work is a great deal easier to scrape than with an 
oil surface, as the oil glazes over the surface and makes it hard to 
start a tool. 



GRINDING AND LAPPING 

GRINDING WHEELS AND GRINDING 
The Commercial Abrasives 

Emery, corundum, carborundum, and alundum are the ordinary 
commercial abrasive materials. They vary in hardness, though it 
does not follow that the hardest grit is the best for cutting purposes; 
the shape and form of fracture of the particles must also be taken 
into consideration. We may imagine a wheel made up from dia- 
monds, the hardest substance in nature, and whose individual ker- 
nels were of spherical form; it is quite obvious that it would be of 
little service as a cutting agent; on the other hand, if these kernels 
were crystalline or conchoidal in form it would probably be the ideal 
grinding wheel. 

Emery is a form of corundum found Avith a variable percentage of 
impurity; it is of a tough consistency and breaks with a conchoidal 
fracture. 

Corundum is an oxide of alimiinum of a somewhat variable piurity 
according to the neighborhood in which it is mined; its fracture is 
conchoidal and generally crystalline. 

Carborundum is a silicide of carbon and is a product of the electric 
furnace; it breaks with a sharp crystalline fracture. 

Alundum is an artificial product, being a fused oxide of aluminum. 
It is of uniform quahty with about 98 per cent, of purity. It breaks 
with a sharp, conchoidal crystalline fracture and has all the tough- 
ness of emery. 

Grit and Bond 

A GRINDING wheel is made up of the "grit" or cutting material, 
and the bond. The cutting efhciency of a wheel depends largely on 
the grit; the grade of hardness depends principally on the bonding 
material used. The efficiency in grinding a given metal is dependent 
largely upon the "temper," or resistance to fracture, and, as noted 
above, upon the character of fracture of the grit or cutting grains of 
the wheel. 

The function of the bond is not only to hold the cutting particles 
of the wheel together and to give the wheel the proper factor of safety 
at the speed it is to be run, but it must also be possible to vary its 
tensile strength to fit the work it is called upon to do. We often hear 
the operator say that the wheel is too hard or too soft. He means 
that the bond retains the cutting teeth so long that they become 
dulled, and this wheel is inefficient; or, in the case of a soft wheel, 
the bond has not been strong enough to hold the cutting teeth and 
they are puUed out of the wheel before they have done the work 
expected. 

208 



GRINDING WHEELS AND GRINDING 209 

The bond to be used for a given operation depends on the wheel 
and work speeds, area of wheel in contact with the work, vibration in 
wheel spindle or work, shape and weight of work, and many other 
like variables. 

Wheels are bonded by what are known as the vitrified, silicate, 
elastic and rubber processes. No one bond makes a superior wheel 
for all purposes; each one has its field. 

The vitrified bond is made of fused clays, is unchanged by heat 
or cold, and can be made in a greater range of hardness than any 
other bond. It does not completely fill the voids between the grains, 
and, therefore, a wheel bonded in this way having more clearance 
than any other, is adaptable for all kinds of grinding except where 
the wheel is not thick enough to vvdthstand side pressure. This bond 
has no elasticity. 

The silicate bond is composed of clays fluxed by silicate of soda at 
low temperatures. It is not as stable as the vitrified bond as regards 
dampness, gives less clearance between grains, and has a range of 
hardness below that of the vitrified in the harder grades. This bond 
has no elasticity and will not make a safe wheel of extreme thinness. 

The elastic bond is composed of shellac and other gums. It com- 
pletely fills the voids of the wheel, has a limited range of grades, has 
a high tensile strength and elasticity, and can be used for the making 
of very thin wheels. The rubber or vulcanite bond has the general 
characteristics of the elastic, but its grades of hardness cannot be 
varied to the same extent and its uses are limited. 

Grain and Grade 

Grinding wheels are made in various combinations of coarseness 
and hardness to meet the variety of conditions under which they 
are used. The cutting material is crushed and graded from coarse 
to fine in many sizes designated by number. Thus the sizes of grain 
used in the Norton wheels are numbered 10, 12, 14, 16, 20, 24, 30, 
36, 46, 50, 60, 70, 80, 90, 100, 120, 150, 180, 200. Finer grades 
known as flour are also used, sometimes these being designated as 
F, FF, FFF, etc. By No. 20 grain is meant a size that wiU pass 
through a grading sieve having 20 meshes to the hnear inch. 

The term "grade" refers to the degree of hardness of the wheel or 
the resistance of the cutting particles imder grinding pressure. A 
wheel from which the cutting particles are easily broken, causing it 
to wear rapidly, is called soft, while one which retains its particles 
longer is called hard. 

Minimum Thickness of Wheels 

Tables 1,2, and 3 by the Norton Company, show minimum thick- 
ness of wheels made by the different processes. A wheel of fine grit 
can be made thinner than a wheel of coarse grit, and have the same 
factor of safety. The minimum thickness depends upon both the 
diameter and the coarseness of the grit used. 

For example, a 24-inch vitrified wheel of No, 10 or No. 12 grain 
should not be made thinner than 2 inches, while if a grain No, 36 or 
finer is used it is considered a safe wheel at i inch thick. 



2IO 



GRINDING AND LAPPING 



Table i. — Minimum Thickness of Elastic Wheels 





Grain 




14 and 16 


20 and 24 


30 and 36 


46 and 60 


70 and finer 


Diameter in 
Inches 


Minimum Thickness of Wheels in Inches 


28 to 30 


f 


3 


3 


f 


1 


24 to 26 


f 


8 


^ 


i 


i 


20 to 22 


h 


h 


t 


t 


f 


16 to 18 


t 


f 


1 
4 


1 
4 


1 

4 


14 to 15 


\ 


i 


A 


A 


A 


10 to 12 


A 


A 


1 




i 


7 to 9 


A 


i 


i 


jg 


tV 


5 to 6 


t\ 


1^ 


T^. 


tV 


A 


3 to 4 


T% 


i 


A 


3V 


3V 


I to 2 


t\ 


' 


A 


3V 


^\ 



Table 2. — Minimum Thickness of Vitrified Wheels 





Grain 




10 and 12 


14 and 16 


20 and 24 


30 


36 


46 


50 to 120 


ISO and finer 


Diameter 
in Inches 




M 


mimum Thickness of Wheel i 


n Inches 




32 to 36 


2h 


2h 


2 


2 


2 


2 


2 


2 


24 to 30 


2 


2 , 


li 


li 


I 


I 


I 


I 


20 to 22 


ih 


ih 


ll 


i\ 


I 


3 

4 


1 


3 


16 to 18 


Ih 


li 


I 


I 


3 


3 


J 


1 


14 to 15 


li 


li 


f 


3 

4 


f 


h 


1 


f 


10 to 12 


li 


li 


1 


^ 


i 


8 


f 


i 


7 tog 


I 


I 


3 
4 




fV 




i 


I 


S to 6 


I 


I 


3 
4 


1 


i 


- 




T% 


3 to 4 




I 


i 


1 


i 


t\ 


i 


i 


I to 2 






3 
4 




1 
4 


i 


i 


i 


Smaller 


















than I In. 














tV 


tV 



GRINDING WHEELS AND GRINDING 



211 



Table 3. — Minimum Thickness of Silicate Wheels 



Grain 



10, 12, 14, 
and 16 



20 and 24 



36 



40 and so 



60 to 

120 



Wire Web 



With 



With- 
out 



With 



With- 
out 



With 



With- 



With 



With- 
out 



With 



With- 
out 



150 
and 
finer 



Without 



Diameter 
in Inches 



Minimum Thickness of WT^eel in Inches 



44 to 48 

38 to 42 

32 to 36 

28 to 30 

24 to 26 

20 to 22 

16 to 18 

14 to 15 

10 to 12 

7 tog 

5 to 6 

3 to 4 

I to 2 



3 


2 


3 


2 


3 


2 


3 




2 


2t 


2 


2h 


2 


25 


2 


2h 








2 


2\ 


li 


2\ 


I§ 


2i 


I^ 


I^ 




2 


2 


2 


2 


I 


2 








l| 


2 


I 


2 


I 


2 








I^ 


A 


I 


Ij 


I 


I-i 








I 


I 


3 


I 


f 


I 


1 






I 


I 




I 


\ 


I 


1 






3 


\ 






\ 


1 


1 






f 


\ 






\ 

1 

i 


3 


f 





Grading of Wheels 

Or the many firms engaged in the manufacture of grinding wheels 
there are probably no two which have a similar method of grading 
or designating the hardness of their wheeels. The Norton Company, 
which is probably the oldest in the field, uses the letter method, which 
may be said to be the simplest. That is, they take M for their me- 
dium-hard wheel and the letters before M denote in regular alphabet- 
ical progression the progressively softer wheels. ISIoreover they use 
a -\- mark for denoting wheels which vary in temper from the stand- 
ards. Thus a wheel may be harder than the standard K, and still 
be not so hard as the standard L; in this case it is known as K -f. 
The Carborundum Company adopts a somewhat similar method 
of grading, the difference being that although M denotes its medium- 
hard wheel the letters before M denote the progressively harder 
grades. Various other American companies use the letter method 
of grading to some extent, but all have individual ideas as to v/hat 
degree of hardness should constitute an M or medium-grade wheel. 
Then there are firms both in America and on the continent of Europe 
which discard the letter method of grading or else use it in conjunc- 
tion with numbers or fractions of numbers such as 2H, i|M and 
so on. 



212 GRINDING AND LAPPING 

The selection of suitable wheels for machine grinding may be said 
to be governed by the following points, namely, the texture of the 
material to be ground, the arc of wheel contact with work and the 
quality of finish required. The first and last of these points can for 
convenience' sake be taken in conjunction. The quality of surface 
finish is dependent on the condition of the wheel face and depth of 
cut rather than on the fineness of the grit in the wheel. A wheel 
of so fine a grit as loo will give an indifferent finish if it is not turned 
true and smooth. 

It may be assumed that for all general purposes the aim in view 
is to procure a wheel which will fulfil tv/o conditions, that is, that it 
shall first remove stock rapidly and at the same time give a decent 
finish. Wheels made from a combination of grit of different sizes 
are the best for this purpose, as may be seen from the following 
explanation. Coarse wheels of an even number of grit will remiove 
stock faster than will fine wheels of an even number, because their 
depth of cut or penetration is greater. They, however, fail in giving 
a high surface finish except in grinding very hard material, because 
they are not compact enough. 

The Combination Grit Wheel 

With the combination wheel the conditions are different and it 
seems better at removing stock than does the coarse, even grit wheel. 
It may be safe to assume from this that something of a grindstone 
action takes place, that is, that the finer particles of grit become 
detached from the bond and both roll and cut in their imprisoned 
condition between the larger particles. For finishing purposes this 
wheel has all the compactness and smooth face of a wheel which 
was made solely from its finest number of grit; and for roughing, 
it enables a depth of cut to be got which is within the capacity of 
its largest kernels. 

With regard to the texture or hardness of material ground it may 
be taken as a general rule that the harder the material is, the softer 
the bond of wheel should be, and that cast iron and hardened steel 
bear some relation to each other as far as grinding wheels are con- 
cerned, for the same wheel is usually suitable for both materials. 

Too large an assortment of wheels is likely to lead to confusion 
and we may take the Norton plain cylindrical grinding machine as 
being a case in point of a limited assortment of wheels; at the same 
time it will be a starting point to illustrate choice of wheels under 
various grinding conditions. In this machine four different grade 
wheels, all of 24 combination grit, are found sufficient for all classes 
of material that it is ordinarily required to grind. These include 
high- and low-carbon steels, cast iron, chilled iron, and bronze or 
composition metals. These wheels are graded J, K, L, and M. 

Hard Wheels 

One of the greatest advantages accruing from grinding is that it 

ignores the non-homogeneity of material and that it machines work 

with the lightest known method of tool pressure, thus avoiding all 

deflections and distortions of material which are a natural result of 



GRINDING WHEELS AND GRINDING 213 

the more severe machining processes. Yet these objects are too 
often defeated by the desire for hard and long-lived wheels. A wheel 
that is too hard or whose bond will not crumble sufficiently under 
the pressure of cut will displace the work and give rise to many 
unforeseen troubles. It is also a prolific cause of vibration which 
is antagonistic to good and accurate work. The advanta.ge claimed 
for it, that it gives a better surface finish, is a deceptive one, for it 
mostly obtains this finish at the expense of accuracy. Quality of 
finish, that is, accurate finish, is merely a question of arranging of 
work speed, condition of wheel face and depth of cut. In the ma- 
chine mentioned the suitability of wheels to materials and conditions 
is found to be as follows, the wheels being in each case of a combi- 
nation of alundum grit: 
For hard chilled iron and large diameters of cast iron and 

hardened steel , 24 J 

For medium chilled iron and medium diameters of cast iron 

and hardened steel and bronze 24 K 

For all grades of steel which are not hardened and for bronze 24 L 
For very low carbon machine steels 24 M 

The table given may, speaking generally, be what would be chosen 
in the way of wheels for the materials given, and in actual practice 
they soon give evidence as to whether they are suitable. It may be 
gathered from the table that diameter of work is a factor in the choice 
of a wheel. This refers to area of wheel contact and is governed 
by what is shown in the table when broad differences of diameter 
occur; for instance, it might be necessary to use the K wheel for a 
large diameter of high carbon steel if the L wheel was evidently too 
hard. 

Speed and Efficient Cutting 

The efficient cutting of a wheel depends very much on the speed 
of the work, and an absence of knowledge in this respect may often 
lead to a suitable wheel's rejection. Revolving the wheel at the 
speed recommended by the maker is the first necessity, and if it is 
found unsuitable after experimenting with various speeds it should 
be changed for a softer or harder one as the conditions indicate. 
Starting from the point that a wheel is desired that shall remove 
the maximum amount of stock with the minimum amount of wear 
on the wheel, the indications and method of procedure may be as 
follows; only it must be understood that this refers to cases where 
an ample supply of water is being delivered at the grinding point. 

If, after trying all reasonable work speeds, a wheel should burn the 
work, or refuse to cut without excessive pressure, or persistently 
glaze the surface of the work, it is too hard for that particular work 
and material and may be safely rejected. If, after trying all reason- 
ably reduced work speeds, a wheel should lose its size quickly and 
show all signs of rapid wear, it is too soft for that particular work and 
material and may be rejected. These indications refer to all ordi- 
nary cases and it may be gathered that the most economical wheel 
is that which acts in such a manner as to be a medium between the 
two cases. There is still another point to bear in mind with regard 
to the size of the grit in the wheel, but which refers more especially 



214 



GRINDING AND LAPPING 



to very hard materials such as chilled iron. Either a coarse or com- 
bination wheel may go on cutting efficiently in roughing cuts because 
pressure is exerted, but may begin to glaze when this pressure is 
•much relieved as in finishing cuts. A careful microscopic scrutiny 
of a wheel that displays this tendency would seem to lead to the fol- 
lowing assumption: 

When a Wheel is Sharp 

The wheel face when newly trued with the diamond tool, which 
is necessary to obtain an accurate finish, shows a promiscuous ar- 
rangement of particles, some of which present points and others 
present a broader face with a rough and granular surface. When 
the wheel is presented to the hard surface of the work the high points 
of this granular face and the sharp contour of the kernels will go on 
cutting until they are dulled and worn down, after which their face 





FIG. 1 

Grinding 
Small Dia. 


FIG. 2 FIG. 3 

Gdnding Large Dia. Grinding 
Flat S.urface. 

Contact of Wheel 


FIG. 4 

Internal Grindi 



area is too great to enter the surface without undue pressure. When 
the wheel has reached this condition the microscope shows these 
broader-faced kernels polished to a metallic luster, which bears out 
the explanation tendered and also makes the remedy quite appar- 
ent. This is to use a wheel of very fine grit for finishing purposes 
in these cases or else keep the coarser wheel in condition by repeated 
dressings with the diamond tool. 

Wheel Contact 

Reference to Figs, i to 4 will show what actual practice requires 
'in the choice of a wheel so far as the question of wheel contact is 
concerned. A wheel is shown in contact with four different vari- 
eties of work, all of which we will suppose to be of the same mate- 
rial, the depth of cut, much exaggerated, being the same in each case. 
In the first case it is a shaft of small diameter, and the wheel contact 
being the smallest the harder grade of wheel would be suitable, com- 
paratively speaking. Assuming that this wheel was found to be 
suitable it would probably require a softer wheel for the next case, 
which is a shaft of larger diameter, and the wheel contact propor- 
tionately greater. To continue the comparison still further, the third 



GRINDING WHEELS AND GRINDING 215 

case shows the wheel engaged in grinding a flat surface, and the 
fourth is a wheel grinding internally. In each case practice demands 
that the wheel shall be progressively softer in bond or grade and is 
some proof of a consistency in the action of grinding wheels. 

The Contact Area of a Wheel 

The most probable explanation of this may be that as the contact 
area increases more work is required from each individual kernel of 
grit and it the sooner becomes dulled; this requires that the bond 
must be more friable both to allow it to escape easily and to minimize 
the pressure required to make the wheel cut as the cutting area 
becomes greater. Following on this reasoning we are able to choose 
a list of wheels which would be suitable for almost all purposes, and 
which would be as follows if of Norton grade: 

For plain cylindrical grinding 

J K L M 
For grinding plane surfaces 

H I J K 
For internal grinding 
F H I J 
This collection of wheels would be suitable for almost any type 
of grinding machines, though when the wheels are exceptionally nar- 
row a grade or one-half grade higher might be possible; it would, 
of course, be a matter for a little trial and experiment. The wheels 
for external cylindrical work may preferably be combination wheels, 
but for plane surface and internal work they are better made of 
single grit, about 36 or 46. The great contact area of wheel in these 
two classes of work is liable to generate much heat so that an open 
and porous wheel is preferable. 

Wheel Pressure and Wear 

As the wheel is a disk built up from a numerous assortment of 
minute cutting tools which are held in position by a more or less 
friable bond, in using it we must bring it to bear on the work with 
a pressure that shall not be so great as to tear these minute tools 
from their .setting until their cutting efficiency is exhausted, for if we 
do so we are wasting the wheel. To gage the exact amount of the 
pressure required is a matter of judgment and experience, though 
where automatic feeds are provided on a machine the right amount 
of pressure or feed is soon determined. It will also be readily under- 
stood that a regular automatic feed is more reliable for the purpose 
than a possibly erratic hand one. The automatic feed may be set 
to give a certain depth of cut at each pass of the wheel, and its amount 
of wear noted; if this wear be found excessive the depth of cut may 
be reduced. It must not be here forgotten that work speed also 
enters into this consideration and that a high work speed will tend 
to wear the wheel excessively; inversely a reduced work speed will 
reduce the amount of wear. Having these points in mind the right 
combination of depth of cut and work speed is soon arrived at, and 
an approximate judgment attained for the future. 



2i6 GRINDING AND LAPPING 

Grinding Allowances 

The amount of stock left for removal by the grinding wheel and 
the method of preparing the work have both much bearing on the 
economic use of grinding wheels, and heavy and unnoticed losses 
often occur through want of a few precautionary measures. The 
necessary amount of stock to leave on a piece of work as a grinding 
allowance depends firstly on the type of machine employed, the class 
of labor engaged in preparing it, and whether it has to be hardened 
or otherwise. 

In powerful machines, which will remove stock rapidly, the grind- 
ing allowance may be anything up to 3^2 inch. There are many 
cases of an especial character when the grinding allowance stated 
may be exceeded to advantage so long as discretion is used. Straight 
shafts may often be ground direct from the black bar of raw material 
■jV inch above finished size, or when shafts of this character must 
have large reduction on the ends they can be roughly reduced in the 
turret lathe while in their black state and finished outright more 
economically in the grinding machine. Very hard qualities of steels 
or chilled rolls are other cases where it is often more economical to 
use the grinding machine without any previous- machining process, 
and though there may be sometimes an alarming waste of abrasive 
material its cost is as nothing compared with other savings that are 
made. 

Grinding allowances for hardened work are usually larger than 
for soft work, to allow for possible distortion; so that individual 
experience alone can determine the amount to be left. It is suffi- 
cient to say that the allowances on case-hardened or carbonized work 
should not be excessive; otherwise the hardened surface may be 
ground away. 

Grinding Hardened Work 

As far as the actual grinding of hardened work goes, it is indis- 
pensable that the whole portion of a piece that is to be ground should 
be roughed over previous to the final finishing; if it is at all possible 
to allow some little time to elapse between the two operations so 
much the better, more especially if it has bent in hardening and been 
afterward straightened; this will allow of the development of any 
strain that may be present. Both for special and standard work in 
a factory a table of grinding allowances can be compiled as a result 
of experience and posted in a conspicuous position. If this be done 
and trouble taken to see that it is adhered to, it will save much trouble 
and be a means of avoiding much unnecessary expense. 

It is necessary to slightly undercut the corners of shoulders so 
as to preserve the corner of the grinder's wheel intact. A piece of 
work should never be prepared in such a manner as to form a radius 
on the corner of the wheel, for to get the wheel face flat again means 
much waste of wheel and wear of diamond. Where fillets or radii 
are necessary they are better got out with a tool, for even if they 
are to be ground they must be turned good to allow the wheel to 
conform to their shape. The only excusable reason for grinding a 
round corner is when the work is hardened or in some special case 
where the expense incurred is warranted. 



GRINDING WHEELS AND GRINDING 



217 



GRINDING ALLOWANCES FOR VARIOUS LENGTHS 
AND DIAMETERS 

Table 4 shows the practice of the Landis Tool Company, in refer- 
ence to grinding allowances. This table covers work up to 12 inches 
diameter, and lengths to 48 inches. 

Table 4. — Allowances for Grinding 
(Landis Tool Co.) 



Length 


3" 


6" 


9" 


12" 


15" 


18" 


24" 


30" 


36" 


42" 


48" 


Diam. 


j .010 


.OIO 


.010 


.010 


.015 


.015 


.015 


.020 


.020 


.020 


.020 


3 


.0x0 


.010 


.010 


.010 


.015 


015 


.015 


.020 


.020 


.020 


.020 


I 


.010 


.010 


.010 


■OIS 


.015 


.015 


.015 


.020 


.020 


.020 


.020 


^i 


.CIO 


.010 


•OIS 


.015 


.015 


•OIS 


•OIS 


.020 


.020 


.020 


.020 


li 


.010 


.015 


•015 


•OIS 


.015 


•OIS 


.020 


.020 


.020 


.020 


.020 


2 


•ois 


.015 


.015 


.015 


.015 


.020 


.020 


.020 


.020 


.020 


.025 


2\ ' 


.015 


.015 


.015 


.015 


.020 


.020 


.020 


.020 


.020 


.025 


.025 


2i 


.015 


.015 


.015 


.020 


.020 


.020 


.020 


.020 


.025 


.025 


.025 


3 


.015 


.015 


.020 


.020 


.020 


.020 


.020 


.025 


.025 


.025 


.o„ 


3§ 


.015 


.020 


.020 


.020 


.020 


.020 


.025 


.025 


.025 


.025 


.025 


4 


.020 


.020 


.020 


.020 


.020 


.025 


.025 


.025 


.025 


.025 


.030 


4i i 


.020 


.020 


.020 


.020 


.025 


.025 


.025 


•025 


.025 


.030 


.030 


5 


.020 


.020 


.020 


.025 


.025 


.025 


.025 


.025 


.030 


.030 


.030 


6 i 


.020 


.020 1 


.025 


.025 


.025 


.025 


.025 


.030 


.030 


.030 


.030 


7 1 


.020 


':::r' 


•025 


.02s 


.025 


-025 


.030 


.030 


.030 


.030 


.030 


' i 


.025 


.025 


.025 


.025 


.025 


.030 


.030 


.030 


.030 


.030 


.030 • 


9 


.025 


.025 


.025 


.025 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


10 1 


.025 


.025 


.025 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


II 1 


•025 
.030 


.025 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


12 


■030 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


.030 


.030 



2l8 



GRINDING AND LAPPING 



OTHER GRINDING ALLOWANCES 

Table 5 gives the allowances of the Brown & Sharpe Mfg. Co. in 
rough turning work for the grinding department. Limit gages of the 
form sho^vn are used, 4:he dimensions in the table covering work up 
to 2 inches diameter. 




Table 5. — Limit Gage Sizes for Lathe 

Work which is to be Finished 

BY Grinding 

(Brown & Sharpe Mfg. Co.) 



Size 


Not go on 


Go on 

• 


Size 


Not go on 


Go on 


Size 


Not go on 


Go on 


Inches 


Inches 


Inches 


. 


0.383 


0.387 


U 


0.94SS 


0.9495 


If 


1.508 


1.512 


I6 


0.4455 


0.4495 


I 




008 


1.012 


ire- 


1.5705 


1.574s 




0.508 


0.512 


irV 




0705 


1.0745 


It 


1-633 


1.637 


I6 


0.5705 


O.S745 


li 




133 


1. 137 


lu 


1.695s 


1.6995 




0.633 


0.637 


Il^6 




1955 


I.I995 


ri 


1.758 


1.762 


ii 


0.6955 


0.6995 


li 




258 


1.262 


m 


1.820S 


1.8245 


f 


0.758 


0.762 


Il\ 




3205 


1.3245 


i^ 


1.883 


1.8875 


H 


0.8205 


0.824s 


I* 




383 


1.387 


rik 


1.9455 


1.949 


i 


0.883 


0.887 


Il'e- 


1-4455 


1-4495 


2 


2.008 


2.0I2 



Use of Water 

Water should be applied at the right spot. This spot must be 
right at the grinding point, whether it be internal, external, or plane- 
surface work, and must be delivered ^vith sufficient force to keep 
the wheel face clean. If this is not done there is a kind of mud 
accumulated at the grinding point, which causes glazing. Water is, 
or should be, used in grinding process not as a means of quenching 
heat but rather to prevent its creation and radiation, and so the 
actual grinding point is the best place to apply it. 

It is a necessary means of keeping the work at an equable tem- 
perature so as to obviate distortion and to make the matter of tak- 
ing dimensions an actuality rather than a guessing matter. This 
applies equally to all kinds of grinding. 

The Use of Diamonds 

Here it is perhaps weU to give the question of diamonds some little 
consideration as they are sometimes a very expensive item. A dia- 
mond is a very essential part of a grinding machine's equipment, for 
in its absence a good and higlily finished grade of work is an impos- 
sibility. It is perhaps unnecessary to state that they should be the 
hardest rough stones procurable, and that the larger they are the 
cheaper they are in the end. With regard to their size: This is a 



GRINDING WHEELS AND GRINDING 



219 



known proportionate element in their price per carat, but a large 
stone allows of a more secure hold in its setting and so the danger 
of losing it is reduced. As a further precaution against this danger 
the diamond tool should always be held by mechanical means when 
using it except in cases- which are unavoidable; this may be in cases 
where profile shapes have to be turned on the wheel face. An 
attempt to turn by hand a perfectly flat face on a wheel, which is 
necessary for finishing, must of a necessity end in failure. 

As a means of preservation of the diamond a full stream of water 
should be run on it when in use and many hght chips are preferable 
to' a few heavy ones. The m.ain thing is to watch that it does not 
get unduly heated, for this is disastrous to it. Where large quanti- 
ties of material have to be removed from a wheel the ordinary wheel 
dresser may be employed to reduce the bulk of the stock, and the 
diamond only used for finishing to shape. 

Setting the Diamonds 

Diamonds may be obtained ready fixed in suitable holders or the 
rough stones maj^ be bought and set by any competent toolmaker. 
The illustrations show various methods by which they may be held 
securely and require but httle explanation. First, Fig. 5 is the 
method most commonly used, the diamond being either peened or 
brazed in position. One disadvantage of this method is that the 
diamond is apt to break with a chance blow of the peening chisel, 
or the heat from brazing will sometimes cause fractures; neither is 
it so easily reset when its point becom.es dulled as are the other 
methods shown. Fig. 6 requires no explanation except that it is 
advisable to pack the diamond with shredded asbestos fiber to act 
as a cushion; this method allows of quick resetting. Fig. 7 consists 



H._.-J 





riG. 5 



FIG. 6 FIG. 7 

Methods of Setting Diamonds 



FIG. 8 



of a small steel cap tapped out to fit the stock as shown. Enough 
shredded asbestos fiber is inserted between the diamond and stock 
to hold it firmly in position. This method also allows of quick and 
safe resetting. The fourth method. Fig. 8, is covered by patent 
rights and its advantage can be seen at a glance; as the diamond 
wears, the small peg containing it can be revolved in the stock to 
present a new cutting edge and be so clamped in position. 



220 



GRINDING AND LAPPING 



Speed Tables, Rules for Surface Speeds, etc. 

The table below gives the number of revolutions per minute at 
which grinding wheels of diameters ranging from i to 60 inches must 
be operated to secure peripheral velocities of 4000, 5000, 5500 and 
6000 feet per minute. Ordinarily a speed of 5000 feet per minute 
is employed, though sometimes the speed is somewhat lower or 
higher for certain cases. 

Grinding Wheel Speeds 





Rev. per Minute! Rev. per Minute Rev. per Minute 


Rev. per Minute 


Diameter 
Wheel 


for Surface Speed for Surface Speed 1 for Surface Speed 


for Surface Speed 


of 4000 ft. 


of 5000 ft. 


of 5500 ft. 


of 6000 ft. 


I Inch 


15,279 


19,099 


21,000 


22,918 


2 Inches 


7,639 


9,549 


10,500 


11,459 


3 Inches 


5,093 


6,366 


7,350 


7,639 


4 Inches 


3,820 


4,775 


5,250 


5,730 


5 Inches 


3,056 


3,820 


4,200 


4,584 


6 Inches 


2,546 


3,183 


3,500 


3,820 


7 Inches 


2,183 


2,728 


3,000 


3,274 


8 Inches 


1,910 


2,387 


2,600 


2,865 


10 Inches 


1,528 


1,910 


2,100 


2,292 


12 Inches 


1,273 


1,592 


1,750 


1,910 


14 Inches 


1,091 


1,364 


1,500 


1,637 


16 Inches 


955 


1,194 


1,300 


1,432 


18 Inches 


849 


1,061 


1,150 


1,273 


20 Inches 


764 


955 


1,050 


1,146 


22 Inches 


694 


868 


950 


1,042 


24 Inches 


637 


976 


875 


955 


26 Inches 


586 


733 


800 


879 


28 Inches 


546 


683 


750 


819 


30 Inches 


509 


637 


700 


764 


32 Inches 


477 


596 


650 


716 


34 Inches 


449 


561 


620 


674 


36 Inches 


424 


531 


580 


637 


38 Inches 


402 


503 


550 


603 


40 Inches 


382 


478 


525 


573 


42 Inches 


364 


455 


. 500 


546 


44 Inches 


347 


434 


475 


5^J 


46 Inches 


332 


41S 


455 


498 


48 Inches 


318 


397 


440 


477 


50 Inches 


306 


383 


420 


459 


52 Inches 


294 


369 


405 


441 


54 Inches 


283 


354 


390 


42s 


56 Inches 


273 


341 


375 


410 


58 Inches 


264 


330 


360 


396 


60 Inches 


255 


319 


350 


383 



The exact speed at which any specified wheel should be run depends 
upon several conditions, such as the t>TDe of machine, character of 
work and wheel, quality of finish desired and various other factors 
referred to at other places in this book. Wheels are ordinarily run in 
practice from about 4090 to 6000 feet per minute, though in some 
cases a speed as high as 7500 feet has been employed. An average 



GRINDING WHEELS AND GRINDING 



221 



speed recommended by most wheel makers is 5000 feet. To allow 
an ample margin of safety it is recommended that wheel speeds 
should not exceed 6000 feet per minute. 

The table of circumferences below will be of service in connection 
with the finding of surface speeds and spindle revolutions per minute. 

Circumferences of Grinding Wheels 



Diameter 


Circumference 


Diameter 


Circumference 


Diameter 


Circumference 


of Wheel 


of Wheel in 


of Wheel 


of Wheel in 


of Wheel 


of Wheel in 


in Inches 


Feet 


in Inches 


Feet 


in Inches 


Feet 


I 


.262 


25 


6.546 


49 


12.838 


2 


•524 


26 


6.807 


50 


13.090 


3 


.785 


27 


7.069 


51 


13.352 


4 


1.047 


28 


7.330 


52 


13.613 


5 


1.309 


29 


7.592 


53 


13.875 


6 


1. 571 


30 


7.854 


54 


14.137 


7 


1.833 


31 


8.116 


55 


14.499 


8 


2.094 


32 


8.377 


56 


14.661 


9 


2.356 


33 


8.639 


57 


14.923 


10 


2.618 


34 


8.901 


58 


15.184 


II 


2.880 


35 


9.163 


59 


15.446 


12 


3.142 


36 


9.425 


60 


15.708 


13 


3.403 


37 


9.687 


61 


15.970 


14 


3.665 


38 


9.948 


62 


16.232 


15 


3.927 


39 


10.210 


63 


16.493 


16 


4.189 


40 


10.472 


64 


16.755 


17 , 


4.451 


41 


10.734 


6S 


17.017 


18 


4.712 


42 


10.996 


66 


17.279 


19 


4.974 


43 


11.257 


67 


17.541 


20 


5. 236 


44 


II. 519 


68 


17.802 


21 


5.498 


45 


II. 781 


69 


18.064 


22 


5.760 


46 


12.043 


70 


18.326 


23 


6.021 


47 


12.305 


71 


18.588 


24 


6.283 


48 


12.566 


72 


18.850 



Thus, to find the surface speed of a wheel in feet per minute : 
Rule. — Multiply the circumference as obtained from the table, 

by the number of revolutions per minute. 

Example. — A wheel 18 inches diameter makes 1060 revolutions 

per minute. What is the surface speed, in feet, per minute? 

4.712 X 1060 = 5000 feet surface speed. 

When the surface speed and wheel diameter are given, to find the 
number of revolutions of the wheel spindle : 

Rule. — Divide the surface speed in feet per minute by the cir- 
cumference. 

Example. — A wheel 24 inches diameter is to be run at 6000 feet 
surface speed per minute. How many revolutions shoidd the wheel 
make? 

6000 ^ 6.283 = 962, number of revolutions per minute the wheel 
should make. 



222 GRINDING AND LAPPING 

GRADING ABRASIVE WHEELS 

The Norton Company uses 26 grade marks, the Carborundum 
Company 19, while the Safety Emery Wheel Company uses 40. The 
following table is a comparison between the grade designations of the 
Norton Company and the Carborundum Company. Intermediate 
letters between the grade designations indicate relative degrees of 
hardness between them; the Norton Company manufacturing four 
degrees of each designation, while the Carborundum Company man- 
ufactures three. 



Norton Co. 


Grade Designation 


Carborundum 


Co. 




A 


"b. 

H 








Extremely or 
Very Soft 

Soft 

Medium Soft 

Medium 

Medium Hard 

Hard 

Extremely or 
Very Hard 








Y 








. U 

Q 






C. 
G 








T 
R 






D. 
F. 




s 






E 


























T 








p 




J 
P 














• 

K 






K 









N 
L 






T, 








N . 


M ... 


M 




















Q 












J 


R 
X 












I 
E 




S 

w 








H 
F 






T . 

y 




G 






U .... 


























Y 








D 




Z 



























The Safety Emery Wheel Company's grade list is an arbitrary one 
with the following designations: 



C. Extra Soft 
A. Soft 

P. Medium 

O. Hard 

E. Extra Hard 



H. Very Soft 
M. Medium Soft 

I. Medium Hard 

N. Very Hard 

D. Special Extra Hard 



GRINDING WHEELS AND GRINDING 



223 



Intermediate figures between those designated as soft, medium 
soft, etc., indicate so many degrees harder or softer, e.g., K\ is one 
degree harder than soft. Af is three degrees harder than soft or 
one degree softer than medium soft. 



Numbers and Grades of Abrasive Wheels 

In the following table for the selection of grades will be found a 
comparison of the grading used by the Norton Company, and that 
of the Carborundum Company: 



Class of Work 



Large Cast Iron and Steel Castings 
Small Cast Iron and Steel Castings 
Large Malleable Iron Castings . . 
Small Malleable Iron Castings . . 

Chilled Iron Castings 

Wrought Iron 

Brass Castings 

Bronze Castings 

Rough Work in General 

General Machine Shop Use 

Lathe and Planer Tools 

Small Tools 

Wood- working Tools 

Twist Drills (Hand Grinding) . . . 
Twist Drills (Special Machines) . 
Reamers, Taps, Milling Cutters, 

etc. (Hand Grind) 

Reamers, Taps, Milling Cutters, 

etc. (Spec. Mach.) 

Edging and Jointing Agricultural 

Implements 

Grinding Plow Points 

Surfacing Plow Bodies 

Stove Mounting 

Finishing Edges of Stoves 

Drop Forgings 

Gumming and Sharpening Saws . 
Planing Mill and Paper Cutting 

Knives 

Car Wheel Grinding 



Norton Co. 



Number 

Usually 

Furnished 



16 to 
20 to 
16 to 
20 to 
16 to 
16 to 
16 to 
r6to 
16 to 
30 to 
30 to 
36 to 
36 to 
36 to 
46 to 

46 to : 

46 to 

16 to 
i6to 
20 to 
20 to 
30 to 
20 to 
36 to 

30 to 
20 to 



30 

20 

30 

20 

30 
30 
30 
30 
46 
46 

100 

60 
60 
60 



Grade 

Usually 

Fvumished 



QtoR 
PtoQ 
QtoR 
PtoQ 
QtoR 
PtoQ 
OtoP 
PtoQ 
PtoQ 
OtoP 
NtoO 
NtoP 
MtoN 
MtoN 
KtoM 

NtoP 

HtoK 

QtoR 
PtoQ 
NtoO 
PtoQ 
OtoP 
PtoQ 
MtoN 

JtoK 
OtoP 



Carborundum Co. 



Number 

Usually 

Furnished 



16 to 24 

20 to 30 
16 to 24 
20 to 30 
16 to 24 
16 to 24 
20 to 36 
20 to 30 
20 to 30 
24 to 36 
30 to 36 
50 to 80 
40 to 60 

60 

50 

50 to 80 

50 to 60 

141 to 24 
20 to 24 
16 to 20 
24 to 30 
24 to 30 

241036 
403-603 

202 — 60 
to 80 
16 to 24 



Grade 

Usually 

Furnished 



GtoH 
GtoH 
GtoH 
Htol 

H 

FtoH 

Htol 

I 

H 
Gto J 
I to J 
I to J 
LtoM 
I to J 
LtoO 

KtoN 

LtoM 

Gto I 

H 

G 

G 

G 
Gtol 
JtoL 

MtoR 
H 



224 



GRINDING AND LAPPING 



THE SHAPES OF WHEELS 

Although grinding wheels are manufactured in a great variety of 
shapes and sizes, there are a few general forms into which they may 
be grouped. Practically'' all of the hundreds of commonly used shapes 
made for the various tj'pes of grinding machines and for the different 
kinds of work come under some one of these classifications, the 
most common of which may be designated as "disk," "cup," "cylin- 




Cylinder 

Fig. 9. — Shapes of Wheels 



-9H— 
Cup 



THE SHAPES OF WHEELS 



225 



der " and " saucer " wheels. These shapes and some of their modifica- 
tions are included in the groups of wheels illustrated in Figs. 9-10. 
These wheels are in most cases made in numerous widths and 
diameters, and the dimensions given in any such instances merely 




Pot Balls 
Fig. 10 — Shapes of Wheels 

show the proportions of one size of wheel selected as t3'pical from 
the comprehensive Hsts of wheel manufacturers' products. 

Of the wheels shown, A and B are plain disks; C is an offset disk 
used on cylindrical grinders for grinding close up to a gear, collar, or 
piston head of large radius; D is a disk wheel for different makes of 



226 GRINDING AND LAPPING . 

tool and roll grinders, E, EE, F, G and H are "ring" wheels which are 
modifications of the disk t3'pe. The two wheels E and EE are made 
on large iron centers and are for use on the Sellers tool grinders. The 
other ring wheels referred to are adapted for mounting on large iron 
centers, and all such wheels are for service on machines where only 
a limited reduction of wheel diameter is permissible. 

The shallow cup wheel / is for drill grinders and the larger, deeper 
cup wheel / is of a t\^e used extensively on knife-grinding machinery. 
.Wheels of this shape and of suitable dimensions, are also used on roll 
and cylindrical grinders, and in the smaller sizes on cutters and 
reamer grinders. 

The wheel K is a plain cylinder for grinding on the end the same 
as the cup wheels. Such cylinders are used in various proportions on 
vertical surface grinders, edge grinders, etc. They are held in ring 
chucks. 

Cup and cylinder wheels are coming more and more into use and 
are already made in a great variety of diameters and widths. On 
certain classes of grinding operations they have marked advantages 
over the regular form of wheel as the same diameter is always main- 
tained, thus avoiding the necessity of a change in speed, and the 
grinding is accomphshed on a flat surface instead of one that is 
curved. 

The cup wheel L is for the Pratt & Whitney vertical surface grinder. 

The small wheels in group M are for internal grinding operations 
in holes of limited diameter. The larger internal wheel R is for the 
Heald cylinder grinder. Three forms of the "saucer" wheel for cutter 
grinders are illustrated at N, and P, and two bevel-edge cup wheels 
are showTi at S, and T, both being made for cutter grinder use. The 
double-edge cup wheel can be used for sharpening both sides of a 
straddle mill without reversing the latter on its arbor; it is also useful 
in such operations as grinding out parallel surfaces, say the jaws of a 
snap gage. ' 

The conical wheel at Q is for a tool grinder and is used principally 
for sharpening pattern makers' gouges which are beveled on the inside 
of the curve. 

Two saw gummers, representative of a number of shapes regularly 
made, are shown at U. These are adapted for sharpening saw teeth 
and grinding dowTi in the "gullet" or concave space between the 
bottoms of the teeth. 

The "pot balls" at N and IF are used in grinding out hollow ware 
such as pots and kettles. These are made in great variety to suit 
spherical receptacles, skillets, flat bottom pots, etc. 

MOUNTING GRINDING WHEELS 

One of the most important considerations in connection with the 
use of grinding wheels is that they shall be properly mounted, upon 
suitably proportioned spindles and between properly designed flanges. 
A wheel which is crowded upon a spindle of weak design, or which is 
cramped between two imperfect flanges that are either too small or 
take a bearing upon the wheel at the wrong point, is subjected to condi- 
tions as likely to cause an accident as is an excessive rate of speed. 



MOUNTING WHEELS 



227 



The vast number of abrasive wheels in use upon the class of ma- 
chines commonly known as bench and floor grinders, grinding wheel 
stands, emery grinders, etc., and which are so generally in service at 
various points about the machine shop, blacksmith shop and foundry, 
makes it desirable that something should be said here in reference to 
the best methods of mounting wheels on such apparatus. 

In the first place, the machine itself should be of rigid construc- 
tion, with spindle of ample proportions; the bearings should be well 
fitted; and kept well oiled so that the arbor will not become over- 
heated and by expanding, break the wheel; and the machine should 
be securely fastened on substantial foundations not only to insure 
safety but in order to secure better results with the wheel. 

The following sizes of spindles are recommended by the Norton 
Company and by some other wheelmakers, except where the grinding 
wheels are extra thick: 

Wheel Spindle 

6 in. diameter and less i in. 

8 in. diameter and less f in. 

10 in. diameter and less f in, 

1 2 in. diameter and less i in. 

14 in. diameter and less I4 P- 

16 in. diameter and less i| in. 

18 to 20 in. diameter if in. 

22 to 24 in. diameter 2 in. 

Larger than 24 in 2I to 3 in. 




Fig. II 



A B 

Right and wrong way to mount v/heels 



The flanges should be reheved as at A in Fig. 11, and they should 
be at least one-half the diameter of the wheel and have a true bear- 
ing at the outer edge. The inner flange should never be loose but in 
all cases should be fixed on the spindle. Under no circumstances 
should the flanges be allowed to be less than one- third the diameter 



228 GRINDING AND LAPPING 

of the wheel. Wheels must not be allowed to run when held only 
by a nut in place of a flange, as the nut is liable to crawl and cause 
accident. 

Compressible washers of pulp or rubber, slightly larger than the 
flanges, should be used between the flanges and the wheel as shown 
at A, Fig. II. These distribute the pressure evenly when the flanges 
are tightened, b}^ taking up any imperfections in the wheel or flanges. 

The hole in the wheel bushing should be 0.005 ii^ch larger than 
standard size spindles. This permits the wheel to sUde on the spindle 
without cramping and insures a good fit not only on the spindle 
but against the inside flange, which is essential. 

The flanges should be tightened only enough to hold the wheel 
firmly, thus avoiding unnecessary strain. 

General Suggestions 

Handle aU wheels with the greatest care in unpacking, storing, 
delivering, etc. Wheels are frequently cracked by rough usage before 
they are ever placed on the grinding machine. The man in charge 
of the storeroom should inspect each wheel before giving it out to the 
workman. 

Wheels should be stored in a dry place. 

A wheel used in wet grinding should not be left overnight partly 
immersed in water. 

When mounting wheels do not screw up the nut too tight; it 
should be set up only enough so that the flanges hold the wheel 
firmly. 

Keep all rests adjusted close to the wheel so that work camiot be 
caught. 

Avoid heavy pressm-e of the work on the wheel when grinding. 

Keep the wheel true by dressing frequently. 

If a wheel vibrates, there is something ^vrong. It should be trued 
up and the boxes should be rebabbitted after the journals are 
trued up. « 

Never hack a wheel; it is unnecessary and dangerous. 

Use wheel guards wherever possible. 

MAGNETIC CHUCKS 

Magnetic chucks have come to be a very necessary part of the 
equipment of any surface grinding machine, whether plain or rotary. 
Before their coming it was customary to bed thin work in wax on the 
platen of a grinder in order to finish the flat sides. Other flat work 
had to be held in "fingers" on special fixtures, and on account of 
their being very thin and easily sprung, it was diflicult to secure 
really accurate work. 

The magnetic chuck holds the thinnest pieces of -iron or steel firmly, 
draws down any shght spring in the work and prevents springing when 
strains are released during the grinding operations. 

The chuck face is divided into magnet poles, separated by babbit 
or other non-magnetic metals, and coils of insulated wire from these 
into electromagnets when current is applied. For rotary work, the 



POLISHING WHEELS 229 

electric current is supplied by brushes running against insulated con- 
tract rings on the outside. Current can be supplied from any incan- 
descent lamp socket on a direct current circuit. 

Alternating current cannot be used. 

A No. o chuck ha\ang a face 10 X 14 inches uses about one-half 
as much power as a 16 candle-power lamp. 

Hints for Using Magnetic Chucks 

The chucks should not be taken apart. 

Nothing but iron or steel can be held on the chucks. 

The holding power depends on the amount of work surface in con- 
tact with the chuck. 

Work can be held on edge by using adjustable back rest. 

Very thin work can be held for grinding on the edges by laying it 
against the back rest and backing it up with a parallel strip. 

Thin work will not hold as well as thick work. 

In packing a num-ber of small pieces on a chuck at one setting, it 
is better to separate them a little Avith strips of non-magnetic material. 

Do not plug up the vent holes in the chuck. 

Keep water away from the switch, the brushes and the interior of 
the chuck. 

Magnetic chucks do not take the place of all other chucks. 

Do not use water on chucks except where they are made for it. 

Chucks are usually wound for no or 220 volts for direct current 
only. 

POLISHING WHEELS 

There are many varieties of polishing wheels in use, the principal 
kinds being kno\\Ti as wooden wheels, compressed wheels, canvas and 
mushn, seahorse and felt wheels. For good work, and economy in 
abrasive, glue and labor cost, wheels and methods must be selected 
to suit the work. 

A few years ago, the wooden wheel covered with leather and turned 
to fit the piece to be polished, was universally used. At the present 
time, the wooden, leather-covered wheel is used largely on fiat sur- 
faces and on work where it is necessary to maintain good edges. 
When this kind of a wheel is made with a double coating of leather, 
it makes a first-class finishing wheel. 

Compressed wheels, or wheels having a steel center are made \vith 
surfaces of leather, canvas or linen. JMany tool shops are equipped 
with these wheels exclusively. They answer all piurposes and are 
safer and more economical than wooden wheels. 

They are also used largely on cutlery and for pohshing chilled plows. 
The compressed wheel is of strong construction, is very durable and 
easily kept in balance. 

Canvas and musUn wheels are used extensively for polishing stoves, 
shovels, plows, brass, cast iron and steel. For roughing out and dry 
fining on irregular pieces, they have proved very satisfactory. They 
hold the abrasive well and require no washing off as they can be 
cleaned with a buff stick or an abrasive brick. 



230 GRINDING AND LAPPING 

Many concerns, such as plow-, shovel- and hoemakers, buy the 
canvas and muslin and make their own wheels. 

Sea-horse wheels are very expensive, most concerns buying the 
hides and making their own wheels. 

Where a high-grade polish is required, there is probably no wheel 
which can compare with the wheel made of sea horse. They are 
largely used on guns, pistols and cutlery. 

Felt wheels are largely used by stovemakers for finishing surfaces. 
Bull neck wheels are also used for this purpose. 

The felt wheels are made from white Spanish and Mexican felt 
and are extensively used for finishing on certain classes of work. 

Care of Polishing Wheels 

Polishing wheels should be kept in perfect balance and running 
true at all times. A wheel out of balance wastes time, glue and 
abrasive, and will not do as good work. 

The most efiicient glue and the best abrasive are the cheapest in 
the long run. 

The glue pots should be kept clean and the glue properly 
cooked before using. 

It is also important to heat the abrasive before applying. 

The wheels should be kept properly cleaned and thoroughly 
covered with the abrasive. 

The wheels should be selected for the particular work the same 
as in grinding and only the wheel best adapted should be used at all 
times. 

Polishing operations are usually divided into three classes: rough- 
ing, dry fining, and finishing or oiling. 

The abrasives used for roughing usually run from numbers 20 to 
80. For dry fining, from numbers 90 to 120. The numbers used 
for finishing run from 150 to XF. 

For both roughing out and dry fining, the polishing wheels should 
be used dry. For finishing, the wheels are first worn down a little 
and then oil, beeswax, tallow and similar substances are used on the 
wheel. This, together with the abrasive, brings up a fine finish. 

Speed of Buffing Wheels 

Wood, leather covered 7,000 ft. per minute 

Walrus 8,000 ft. per minute 

Rag wheels 7,000 ft. per minute 

Hair-brush wheels 12,000 ft. per minute 

Ohio grindstone 2,500 ft. per minute 

Huron grindstone 3,500 ft. per minute 



LAPPING 231 



LAPPING 

Lapping may be defined as the process of finishing the surface of 
a piece of work by means of another piece of material, called a lap, 
the surface of which is charged with an abrasive. 

Laps are roughly divided into three general classes. First, those 
where the form of the lap makes a line contact with the work, and 
the work is, if cylindrical, revolved to develop the cylindrical form, 
or, if straight, in one direction, is moved back and forth under the 
lap. Second, those which are used for straight surfaces with a full 
contact on the lap, and third, those which are used for male and 
female cylindrical surfaces with a full contact on the lap. In all 
cases the material from which the lap is made must be softer than 
the work. If this is not so, the abrasive will charge the work and 
cut the lap, instead of the lap cutting the work. 

The first class is used in the place of emery wheels, either where 
the work is too small to use an ordinary wheel or where a form is 
to be ground on the work and an emery wheel will not keep its shape. 
They are usually made of machinery steel and the abrasive used is 
crushed diamond rolled into the surface. In rolling in the diamond 




Fig. I. — A Lapping Plate for Flat Work 

dust the sharp corners of the particles cause them to bed securely 
into the surface of the lap, and if a good quality of diamond is used, 
a lap will grind all day without recharging. Oil is used to lubricate 
the work and carry away the dust from the grinding. If a diamond 
lap is run dry the particles of diamond tear and raise "burs" in the 
work, which strip the lap very quickly. The speed should be about 
two-thirds that for an emery wheel of the same size; for if it is ex- 
cessive, the lap will wear smooth and glaze instead of cutting. This 
kind of lap is used mainly in watch and clock shops, and shops mak- 
ing watch tools, sub-press dies, and similar work. 

Lapping Flat Surfaces 

In lapping flat surfaces, which are usually on hardened steel, a 
cast-iron plate is used as a lap and emery as an abrasive. In order 
that the plate may stay reasonably straight, it should either be quite 
thick, or else ribbed sufficiently to make it rigid, and in any case it 
should be supported on three feet, the same as a surface place. For 



232 GRINDING AND LAPPING 

rough work or "blocking down," as it is called, the lap works better 
if scored with narrow grooves, about J inch apart, both lengthways 
and crossways, thus dividing the plate into small squares, as in Fig. i. 
The emery is sprinkled loosely on the block, wet with lard oil 
and the work rubbed on it; care is taken to press hardest on the high- 
est spots. The emery and oil get in the grooves, and are continually 
rolhng in and out, getting between the plate and the work and are 
crushed into the cast iron, thus charging it thoroughly in a short 
time. About No. loo or No. 120 emery is best for this purpose. 

After blocking down, or if the work has first been ground on a 
surface grinder, the process is different. A plain plate is used 
with the best quality of flour of emery as an abrasive, as the least 
lump or coarseness will scratch the work so that it will be very hard 
to get the scratches out. Instead of oil benzine is used as a lubri- 
cant and the lap should be cleaned off and fresh benzine and emery 
apphed as often as it becomes sticky. The work should be tried 
from time to time with a straight-edge and care taken not to let the 
emery run in and out from under the work, as this will cause the edges 
to abrade more than the center, and will especially mar the corners. 
After getting a good surface, the plate and work should be cleaned 
perfectly dry, and then rubbed. The charging in the plate will 
cut just enough to remove whatever emery may have become charged 
in the work, will take away the dull surface and leave it as smooth as 
glass and as accurate as it is possible to produce. 

Laps for Holes 

In lapping holes various kinds of laps are used, according to the 
accuracy required, and the conditions under which the work is done. 
The simplest is a piece of wood turned cylindrical with a longitu- 



^a 



m 



n^: 



Fig. 2. — Laps for Holes 

dinal groove or split in which the edge of a piece of emery cloth is 
inserted. This cloth is wound around the wood until it fills the hole 
in the work. This is only fit for smoothing or enlarging rough holes 
and usually leaves them more out of round and bell-mouthed than 
they were at first. Another lap used for the same purpose — and 
which produces better results — is made by turning a piece of cop- 
per, brass, or cast iron to fit the hole and splitting it longitudinally 
for some distance from the end. Loose emery is sprinkled over it, 



LAPPING 233 

with lard oil for a lubricant, and a taper wedge is driven into the 
end for adjustment as the lap wears. 

For lapping common driU bushings, cam rolls, etc., in large quan- 
tities, where a little bell-mouthing can be allowed, and yet a reason- 
ably good hole is required, a great many shops use adjustable copper 
laps made with more care than the above. One way of making 
them is to split the lap nearly the whole length, but leaving both 
ends soUd. One side is drilled and tapped for spreading screws 
for adjustment. Either one screw half-way down the split may be 
used or two screws dividing the split into thirds. Another and 
better means of adjustment is to drill a small longitudinal hole a 
little over half the length of the lap, enlarge it for half its length, 
and tap the large end for some distance. This is done before split- 
ting. Into this hole a long screw with a "taper point is fitted so that 
when tightened it tries to force itself into a small hole, thus spread- 
ing the lap. 

For nice work there is nothing better than a lead lap. Lead charges 
easily, holds the emery firmly and does not scratch or score the work. 
It is easy to fit to the work and holds its shape weU for light cuts. 
Under hard usage, however, it wears easily. For this reason, while 
laps for a single hole or a special job are sometimes cast on straight 
arbors, where much lapping is done it is customary to mold the laps 
to taper arbors with means for a slight adjustment. After any exten- 
sive adjustment the lap will be out of true and must be turned off. 
All o£ these laps, as shown in Fig. 2, are to be held by one end in 
a lathe chuck, and the work run back and forth on them by hand, 
or by means of a clamp held in the hand. If a clamp is used care 
should be taken not to spring the work. 

How to Do Good Lapping 

There are several points which must be taken into consideration 
in order to get good results in lapping holes. The most important 
is that the lap shall always fill the hole. If this condition is not com- 
phed with the weight of the work and the impossibility of holding 
it exactly right will cause it to lap out of round, or if it is out of round 
at the start the lap mil be free to follow the original surface. If the 
lap fits, it will bear hardest on the high spots and lap them off. Next 
in importance to getting a round hole is to have it straight. To 
attain this end the lap should be a little longer than the work, so 
that it will lap the whole length of the hole at once, and not have a 
tendency to follow any curvature there may be in it. What is known 
as bell-mouthing, or lapping large on the ends, is hard to prevent, 
especially if the emery is sprinkled on the lap and the work shoved 
on it while it is running. The best way to avoid this condition when 
using cast-iron or copper laps, which do not charge easily, is to put 
the emery in the slot, near the center of the lap, and after the work 
is shoved on squirt oU in the slot to float the emery. Then, when 
the lathe is started the emery wiU carry around and gradually work 
out to the ends, lapping as it goes. Where lead is used the emery 
can be put on where it is desired to have the lap cut and roUed in 
with a flat strip of iron. It will not come out easily, so will not spread 



234 GRINDING AND LAPPING 

to any extent, and it is possible with a lap charged in this manner 
to avoid cutting the ends of the hole at all. The work should always 
be kept in motion back and forth to avoid lumping of the emery 
and cuttings which will score grooves in the work. 

Ring Gage and Other Work 

Ring gages are lapped with a lead lap. They are first ground 
straight and smooth to within .0005 inch of size, and then, when 
lapped, are cooled as well as cleaned, before trying the plug, by 




Fig. 3. — A Lap for Plugs 

placing them in a pail of benzine for a long enough time to bring 
them down to the temperature of the room. Some shops leave a 
thin collar projection from each side around the hole, so that, if there 
is any bell-mouthing, it will be in these collars, which are ground 
off after the lapping is done. 

Other metals are lapped in this same manner, except that the 
abrasive is different. Cast iron is lapped with emery, but ch'arges 
to some extent. This charging can be taken out without changing 
the work materially by rubbing it by hand with flour of emery cloth. 
In lapping bronze or brass, crocus and Vienna lime are used. Crocus 
is used with a cast-iron or lead lap, and the charging is removed by 
running the work for a few seconds on a hardwood stick which fits 
the hole. Unslaked Vienna lime, freshly crushed, is used with a 
lead or hardwood lap, and does not charge. It does a nice job, but 
is very slow, and is only used in watch factories. 

For lapping plug gages, pistons, and other cylindrical articles, a 
cast-iron lap is usually used, split and fitted with a closing and a 
spreading screw, as shown in Fig. 3. Sometimes, where a very fine 
finish is required, or where the work is not hardened, the hole is 
made larger than the work, and a lead ring cast into it. 

DIAMOND POWDER IN THE MACHINE SHOP 

The diamond used for this purpose, costing 85 cents per carat, is 
an inferior grade of diamond, not so hard as the black diamond used 
for drills and truing emery wheels, and not of a clear and perfect 
structure to permit it to enter the gem class. Many are a mixed 
black and white, others yellow and some pink; many are clear but 
flaky. Then there is the small debris from diamond cutting, which 
is reduced to powder and sells somewhat cheaper; but some find 
it more economical to use the above and powder it themselves, as 
the debris from diamond cutting is of a flaky nature, and does not 
charge into the lap so well. 



DIAMOND POWDER IN THE MACHINE SHOP 235 

Assuming there is 25 carats to reduce to powder, proceed as follows: 
Into a mortar, as shown at Fig. 4, place about 5 carats, using an 
8-ounce hammer to crush it. It takes from 3 to 4 minutes' steady- 
pounding to reduce it to a good average. Scrape the powder free 
from the bottom and the sides and empty into one half pint of oil. 
The oil used is the best olive oil obtainable, and is held in a cup- 
shaped receptacle that wiU hold a pint and one half. The 25 carats 
being reduced to powder, and in the oil, stir it until thoroughly mixed, 
and allow to stand 5 minutes; then pour off to another dish. The 
diamond that remains in the dish- is coarse and should be washed 
in benzine and allowed to dry, and should be repounded, unless 
extremely coarse diamond is desired. In that case label it No. o. 
Now stir that which has been poured from No. o, and allow to stand 
10 minutes. Then pour off into another dish. The residue will 
be No. I. Repeat the operation, following the table below. 

The settlings can be put into small dishes for convenient use, 
snough oil sta>ang with the diamond to give it the consistency of 
paste. The dishes can be obtained from a jewelers' supply house. 

Table for Settling Diamond Powder 

To obtain No. o — 5 minutes. To obtain No. 3 — i hour. 
To obtain No. i — 10 minutes. To obtain No. 4 — 2 hours. 
To obtain No. 2 — 30 minutes. To obtain No. 5 — 10 hours. 
To obtain No. 6 — until oil is clear. 
Diamond is seldom hammered; it is generally rolled into the 
metal. For instance, several pieces of wire of various diameters 
charged with diamond may be desired for use in die work. Place 
the wire and a small portion of the diamond between two hardened 
surfaces, and under pressure roll back and forth until thoroughly 
charged. No. 2 diamond in this case is generally used. Or one can 
form the metal any desired shape and apply diamond and use a roll, 
as Fig. 6, to force the diamond into the metal. This is then a 'file 
which will work hard steel, but the moment this diamond file, or lap, 
is crowded it is stripped of the diamond, and is consequently of no 
use. It is to be used with comparatively light pressure. 

Diamond Laps 

Copper is the best metal. It takes the diamond readily, and 
retains it longer than other metals; brass next, then bessemer steel. 
The latter is used when it is wished to preserve a form that is often 
used. 

For sharpening small, flat drills, say 0.008 to o.ioo, a copper lap 
mounted on a taper shank, as in Fig. 5 and charged on the face with 
No. 2 diamond, using pressure on the roll, makes a most satisfactory 
method of sharpening drills. The diamond lasts for a long time if 
properly used, and there is no danger of drawing the temper on the 
drill. It is much quicker than any other method of sharpening. 

To charge the lap use the roll. Fig. 7, supported on a T rest press- 
ing firmly against the lap, being careful to have the roll on the 
center; otherwise instead of charging the lap it will be grinding the 



236 



GRINDING KNB LAPPING 



roll. The diamond may be spread either on the lap or the roll, and 
the first charging usually takes twice the amount of diamond that 
subsequent charging takes. To avoid loss of diamond, wash the 





FIG.5U 

FIG. t) 

FIG. 7 
FIG. 4 

Diamond Lap Tools 

lap in a dish of benzine kept exclusively for that purpose. This can 
be reclaimed by burning the metal with acids, and the diamond can 
be. resettled. 

For the grinding of taper holes in hard spindles or for position 
work in hard plates, where holes are too small to allow the use of 
emery wheels, No. i diamond does the work beautifully. Or if it 
is wished to grind sapphire centers or plugs as stops, etc., a bessemer 
lap made in the form of a wheel and charged with diamond on the 
diameter does the work nicely. 

Nos. 5 and 6 diamond are used on boxwood laps, mounted on 
taper plugs or chucks, and the diamond smeared on with the finger. 
The lap is run at high speed and used for fine and slow cutting 
which also gives a high pohsh. 



REAMER AND CUTTER GRINDING 
Reamer Clearances 

After constant experimenting for a period of more than a year, 
the Cincinnati Milling Machine Company succeeded in establishing 
tables for four styles of reamers for obtaining what they consider to 
be the best clearances, the object being to grind clearances on reamers 
which would ream the greatest number of smooth holes with a mini- 
mum amount of wear. The four styles of reamers are as follows: 
Hand reamers for steel, hand reamers for gray iron and bronze, chuck- 
ing reamers for gray iron and bronze, chucking reamers for steel. 
The company uses adjustable blade reamers almost exclusively, all of 
which are ground in the toolroom on their universal cutter and tool 
grinder. High speed steel reamers cUng to nickel steel and do not 
cut it as well as carbon steel. 



REAMER AND CUTTER GRINDING 237 

Fig. I is a cross-section of a hand reamer. Two clearance lines, 
A and B, are ground on the blades, a being the cutting clearance 
and b the second clearance called for in the table. The object of 
giving the adjustment for the second clearance so minutely is to pro- 
vide a proper width of land, which equals .025 inch on all hand reamers 
for gray iron or bronze, and 0.005 i^^ch on hand reamers for steel. 




Fig. I . — Cross-section of Hand Reamer 

Chucking reamers for gray iron and bronze have, in this system, 23- 
degree beveled ends as shown in Fig. 2, and are provided with two 
clearances along the blades, for which the settings are given in Table 
3. The beveled ends have only one clearance which is equal to the 
second clearance given in Table 3. Fig. 3 shows a chucking reamer 
for reaming steel. In these reamers the blades are circular ground 
to the exact size of hole to be reamed and without clearance, the 45- 



I'v^ 



Fig. 2. — Chucking Reamer Fig. 3. — Chucking Reamer 

Blade for Gray Iron and Bronze Blade for Steel 

degree beveled ends only having clearance as given in Table 4. On 
all reamers of this style the blades are ground from .015 to .020 inch 
below size half of their length toward the shank end. 

In grinding the clearances for the various kinds of reamers as 
given in Table i, 2, and 3, the tooth rest is held stationary on the 
emery wheel hea4 of the grinder, while in grinding the 45-degree 
beveled ends on the chucking reamers for steel, the tooth rest is 
supported from the grinder table and travels with the work. The 
front end of the hand reamer blades are tapered about 0.004 pei 
inch. The back ends of the blades are also slightly tapered to pre- 
vent injuring the holes when backing the reamer out. 



238 



GRINDING AND LAPPING 







REAMER CLEARANCE 






Set Tooth Rest 










Below Work 


Ground with Cup Wheel 3" 


dia.— Tooth Rest to be Set Central 


Holding Centers. 


with Emery Wheel Spindle. Set Work holding Centers above 


Amount given 


Emery Wheel Center by 


\mount given below in Tables No. 


Below in Table 


1-2 and 3 






No. 4 




TABLE I 


TABLE 2 


TABLE 3 


TABLE 4 


Hand Reamer for Steel 


Hand Reamer 


Chucking 


Chucking Ream- 


Cut'g 


Clearance Land 


for Cast Iron 


Reamer for 


ers for Steel Cir- 


.006 Wide 


and Bronze 


Cast Iron and 


cular Ground 






Cut'g Clear- 


Bronze Cut'g 








ance Land 


C 1 e a r a n ce 








.025 Wide 


Land .025 
Wide 




u 


Ii 


li 




Is 


.Is 


a 







<u § 






11 


^i 


11 


y 2 




m 


















.^(^ 


S^ 


0^ 


S^ 


S^ 


fe^ 


feC 


cw3 


en 


ta . 


fe 


^ 


fa 


fa 


fa 


< 


fa 


i" 


.012 


.052 


.032 


.072 


.040 


.080 


45 Degi-ees 


.080 


¥ 


.012 


•057 


.032 


.072 


.040 


.080 




.080 


.012 


.062 


.032 


.072 


.040 


.090 




.090 


K 


.012 


.067 


•035 


•095 


.040 


.100 




.100 


* 1 


.012 


.072 


•035 


•095 


.040 


.100 




.100 


f: 


.012 


.077 


•037 


•09s 


•045 


.125 




•125 


.012 


.082 


.040 


.120 


•045 


• 125 




■125 


it" 


.012 


.087 


.040 


.120 


•045 


•125 




•125 


I " 


.012 


.092 


.040 


.120 


•045 


.125 




.125 


ItY 


.012 


.097 


.040 


.120 


•045 


.125 




.125 


Ij" 


.012 


.102 


.040 


.120 


•045 


• 125 




.125 


^K 


.012 


.106 


.042 


.122 


•045 


•125 




•125 


li" 


.012 


.112 


.045 


.145 


.050 


.160 




.160 


If 


.012 


.118 


•045 


• 145 


.050 


.160 




.160 


.012 


.122 


•045 


• 145 


.050 


.160 




■175 


:j'" 


.012 


.127 


•045 


• 145 


•05 s 


•175 




•175 


.012 


.132 


.048 


.168 


•05.S 


.175 




.175 


ItV 


.012 


•137 


.050 


.170 


•055 


•175 




•175 


If" 


.012 


.142 


.050- 


.170 


.060 


.200 




.200 


iir 


.012 


.147 


.050 


.170 


.060 


.200 




.200 


ii " 


.012 


.152 


.052 


.192 


.060 


.200 




.200 


lir 


.012 


•157 


.052 


.192 


.060 


.200 




.200 


ij " 


.012 


.162 


.056 


.196 


.060 


.200 




.200 


lir 


.012 


.167 


.056 


.196 


.064 


.200 




.200 


2 " 


.012 


.172 


.056 


.216 


.064 


.224 




•225 


2lV' 


.012 


.172 


.056 


.216 


.064 


.224 




.225 


^^:; 


.012 


.172 


•059 


.219 


.064 


.224 




.225 


2fg" 


.012 


.172 


•OS9 


.219 


.064 


.224 




.225 


2i" 


.012 


.172 


.063 


.223 


.064 


.224 




.225 


ff" 


.012 


.172 


.063 


.223 


.064 


.224 




.225 


.012 


.172 


.063 


.223 


.068 


.228 




.230 


•^^< 


.012 


.172 


.063 


.223 


.068 


.228 




.230 


2i" 


.012 


.172 


.065 


.225 


.072 


.232 




.230 


2lV' 


.012 


.iy2 


.065 


.225 


.072 


•232 




.230 


2I" 


.012 


.172 


.065 


.225 


•07S 


•235 




.235 


ff^ 


.012 


.172 


.065 


.225 


•07S 


•235 


45 


•235 


.012 


.172 


.065 


.225 


.077 


•237 


45 


.240 




Mount Tooth R( 


;st on Emery Whe 


el Head 


Mount Tooth Rest 
on Table of Machine 



REAMER AND CUTTER GRINDING 



239 





REAMER CLEARANCE 


Set Tooth Rest 








Below Work 


Ground 


vith Cup Wheel 3" 


dia.— Tooth Rest to be Set Central 


Holding Centers. 


with E 


mery Wheel Spindle. Set Work holding Centers above 


Amount given 


Emery Wheel Center by Amount given below in Tables No. 


Below in Table 


1-2 and 3 




No. 4 




TABLE I 


TABLE 2 


TABLE 3 


TABLE 4 


Hand Reamer for Steel 


Hand Reamer 


Chucking 


Chucking Ream- 


Cut'g 


Clearance Land 


for Cast Iron 


Reamer for 


ers for Steel Cir- 


.006 Wide 


and Bronze 


Cast Iron and 


cular Ground 






Cut'g Clear- 


Bronze Cut'g 








ance Land 


Clearance 








.025 Wide 


Land .025 
Wide 






M4, 


"O D 


s>fio 


'O aj 


W 


"^ 


C"« 


M 


u 


c z 




C 


C 


C 


c S 





CUD 


■5 ^ 


a 


■•3 a 


R c 


"z; ^ 


a 


•■= B'si 


B 
.^1 


3 M 

0^ 


r^2 






3 d 


si 




3 5 c 


t/2 


fa 


fa 


fa 


fa 


fa 


fa 


< 


fa 


^\K 


.012 


.172 


.06s 


.225 


.077 


.237 


45 Degrees 


.240 


2^ 


.012 


.172 


.070 


.230 


.080 


.240 


45 


.240 


2\r 


.012 


.172 


.070 


.230 


.080 


.240 


45 


.240 


3 , . 


.012 


.172 


.072 


.232 


.080 


.240 


45 


.240 


H<. 


.012 


.172 


.072 


.232 


.080 


.240 


45 


.240 


Al 


.012 


.172 


•075 


•235 


.083 


.240 


45 " 


.240 


3p 


X)I2 


.172 


•07s 


•235 


.083 


.243 


45 


.240 


H 


.012 


.172 


.078 


.238 


.083 


.243 


45 " 


•245 


W^ 


.012 


.172 


.078 


.238 


.087 


•243 


45 


•245 


.012 


.172 


.081 


.241 


.087 


•247 


45 


.245 


W" 


.012 


.172 


.081 


.241 


.090 


.247 


45 " 


.245 


.012 


.172 


.084 


•244 


.090 


.250 


45 


.250 


^K 


.012 


.172 


.084 


.244 


.090 


.250 


45 


.250 


si " 


.012 


.172 


.0S7 


.247 


•093 


•253 


45 


.250 


t'' 


.012 


.172 


.087 


•247 


■093 


.253 


45 " 


.250 


.012 


.172 


.090 


.250 


.097 


.257 


45 


•255 


^W„ 


.012 


.172 


.090 


.250 


.097 


.257 


45 '' 


•255 


^\ , 


.012 


.172 


•093 


•253 


.100 


.260 


45 


.255 


3iC 


.012 


.172 


•093 


•253 


.100 


.260 


45 " 


.255 


4 


.012 


.172 


.096 


.256 


.104 


.264 


45 " 


.260 


4?% 


.012 


.172 


.096 


.256 


.104 


.264 


45 


.260 


a\ " 


.012 


.172 


.096 


.256 


.104 


.264 


45 


.260 


4iV' 


.012 


.172 


.096 


.256 


.106 


.266 


45 


.260 


A\" 


.012 


.172 


.096 


.256 


.106 


.266 


45 " 


.265 


4tV' 


.012 


.172 


.096 


.256 


.106 


.266 


45 " 


.265 


4l' 


.012 


.172 


.096 


.256 


.108 


.268 


45 " 


.265 


4iV' 


.012 


.172 


.096 


.256 


.108 


.268 


45 " 


.265 


Ah" 


.012 


.172 


.100 


.260 


.108 


.268 


45 " 


.265 


^C' 


.012 


.172 


.100 


.260 


.108 


.268 


45 


.265 


.012 


.172 


.100 


.260 


.110 


.270 


45 


.270 


C" 


.012 


.172 


.100 


.260 


.110 


.270 


45 


.270 


.012 


.172 


.104 


.264 


.114 


•274 


45 


.275 


4?«' 


.012 


.172 


.104 


.264 


.114 


.274 


45 " 


.275 


41 


.012 


.172 


.106 


.266 


.116 


.276 


45 " 


.275 


A\%" 


.012 


.172 


.106 


.266 


.116 


.276 


45 " 


.275 


^3 " 


.012 


.172 


.110 


.270 


.118 


.278 


45 " 


.275 


5I " 


.012 


.172 


.118 


278 












Mount 


Tooth Re 


St on En: 


lery Whe 


dHead 




Mount To 
on Table of 


oth Rest 
Machine 



240 



GRINDING AND LAPPING 





liK}^^:.it 


<~ 


--JX 




:>;:%. 






'lil 


r^ , 


ilii\^x^^ 


.^is 


Z-t i 


Eu^%^A C 1 j 


^^i 


r^-'T"" 


1 ~^MV B-J7_; 


•meyy: 


1 W(jri 


1 -',--■■.■:■'■■/ 


/ • 


.^fceej.: 




1 .-:•..■-■/ 


/ 1 




■^\ v — 


-0 -■ ;■ -y 


t^ Work 




V/^^s^^ 


■^.^^ 


V/v 


Tooth Kest 




Tooth Best 


^-Nx- 


Cup Wheel Clearance Table 


Disk Wheel Clearance Table 


For setting tooth rest to obtain 


Giving distance B for setting 


5° or 7° clearance when grinding 


work centers and tooth rest be- 


peripheral teeth of milling cutters 


low center of wheel spindle to 


with cup-shaped wheel. Tooth 


obtain 5° or 7° clearance with 


rest is set below work centers as 


wheels of different diameters 


at A , the distance being found in 


when grinding with periphery of 


.the table below. 


disk wheel. 


Dia. 


For 5° 


For 7° " 


Dia. of 
Emery 
Wheel 
Inches 


For 5° 


For f 


Cutter 


Clearance 


Clearance 


Clearance 


Clearance 


Inches 


A = 


A = 


B = 


B = 


i 


.Oil 


.015 


2 


•0937 


.125 


f 


.015 


.022 


2i 


.099 


.141 


h 


.022 


.03Q 


2\ 


.110 


.156 


t 


.028. 


•037 


2f 


.125 


.172 


1 


•033 


.045 


3 


.132 


.187 


I 


•037 


.052 


3i 


.143 


.203 


I 


.044 


.060 


z\ 


.154 


.219 


li 


.055 


•075 


Z\ 


.165 


•234 • 


l^ 


.066 


.090 


4 


.176 


.250 


If 


.077 


.105 


4i 


.187 


.265 


2 


.088 


.120 


4i 


.198 


.281 


2i 


.099 


.135 


4f 


.209 


•297 


A 


.110 


.150 


5 


.220 


.312 


2f 


.121 


.165 


5i 


.231 


.328 


3 


.132 


.180 


5^ 


.242 


•344 


z\ 


.154 


.210 


5f 


.253 


•359 


4 


.176. 


.240 


6 


.264 


.375 


4^ 


.198 


.270 


6i 


.275 


•390 


5 


.220 


.300 


6i 


.286 


.406 


51 


.242 


'7>Zo 


61 


.297 


.421 


6 


.264 


.360 


7 


.308 


•437 



OILSTONES 241 

OILSTONES AND THEIR USES 
Natural Stones 

The following particulars regarding the well-known Arkansas and 
Washita stones are given by the Pike JManufacturing Company: 

Arkansas stones are made from rock quarried in the Ozark moun- 
tains of Arkansas, and are prepared for commercial purposes in two 
grades, hard and soft. 

Hard Arkansas is composed of pure silica and its sharpening 
qualities are due to small, sharp-pointed grains, or crystals, of hex- 
agonal shape, which are much harder than steel and wiU, therefore, 
cut away and sharpen steel tools. The extreme fineness of texture 
makes this stone, of necessity, a slow cutter, but in the very density 
of the crystals of which it is composed lies its virtue as a sharpener. 

Soft Arkansas stone is not quite so fine-grained and hard as the 
hard Arkansas, but it cuts faster and is better for some kinds of 
mechanical work. It is especially adapted for sharpening the tools 
used by wood carv^ers, file makers, pattern makers, and aU workers 
in hard wood. 

Washita stone is also found in the Ozark mountains in Arkansas 
and is similar to the Arkansas stone, being composed of nearly pure 
silica, but is much more porous. It is known as the best natural 
stone for sharpening carpenters' and general wood workers' tools. 
This stone is found in various grades, from perfectly crystallized 
and porous grit to vitreous flint and hard sandstone. The sharp- 
ness of the grit depends entirely upon its crystallization, the best 
oilstones being made from very porous crystals. 

In addition to the regular rectangular sections, natural stones are 
made in such shapes as square, triangular, round, flat, bevel, dia- 
mond, oval, pointed, knife edge. 

Artificial Oilstones 

Artificial oilstones are manufactured in a multitude of shapes and 
sizes and are adapted for sharpening all kinds of tools. Such stones 
ard made by the Norton Company of alundum and crystolon, the 
former being known as India oilstones, the latter as crystolon sharp- 
ening stones. Similar shapes are manufactured by the American 
Emery Wheel Works, and the Carborundum Company also makes 
such stones in great variety. 

The stones are made in three grades or grits, coarse, medium and 
fine. The coarse stones are used in machine shops for sharpening 
very dull or nicked tools, machine knives, and for general use where 
fast cutting is desired. 

Medium stones are sharpening mechanics' tools in general, more 
particularly those used by carpenters and in wood-working shops. 

Fine stones are adapted for engravers, die workers, cabinet makers 
and other users of tools requiring a very fine, keen-cutting edge. 

Of the great variety of shapes and sizes a number adapted espe- 
cially for machine shop purposes are illustrated half size in Fig. i . Of 
these, Nos. o, i, i|, 2, 24 and 29 are for sharpening lathe and planer 



242 



GRINDING AND LAPPING 



tools, and for use after grinding; Nos. 23, 25, 56 and 56^ for reamers; 
Nos. 13, 14 and 15 for taps; Nos. 4, 5, 6, 7, 8, 9, 10, 11, 12 and 26 
for dies. 




No.O - 8x2x1 

No.29 -e'xs'xi' 



N0.2 



Fig. I. — Shapes of Oilstones 

A few shapes and sizes for curved-edge wood-working tools are Nos. 
ro, iij 12, 13, 14, 15, in Fig. i. Rectangular shapes for straightedge 



SHAPES OF OILSTONES 243 

tools like chisels, plane bits, planer knives, scrapers, paper-cutting 
knives and other tools with broad flat edges are Nos. o, i, i^, 2, 24, 
29, in Fig. I. 




No.58 No.51 

Fig. 2. — Shapes of Oilstones 

Fig. 2 shows some of the sizes and shapes particularly adapted for 
mold and die work, watch and clock makers' tools, etc. Other 



244 GRINDING AND LAPPING 

shapes suitable for such purposes are shown by Nos. 4, 5, 6, 7, 8, 9 
and 26 in Fig. i and No. 51 in Fig. 2. 

How to Care for Oilstones 

Like anything else, an oilstone can be ruined' by wrong treatment 
and lack of care. 

There are three objects to be attained in taking good care of an 
oilstone: first, to retain the original life and sharpness of its grit; 
second, to keep its surface flat and even; third, to prevent its glazing. 

To retain the original freshness of the stone, it should be kept 
clean and moist. To let an oilstone remain clry a long time, or 
expose it to the air, tends to harden it. A new natural stone should 
be soaked in oil for several days before using. If an oilstone is kept 
in a dry place (most of them are) it should be kept in a box with 
closed cover, and a few drops of fresh, clean oil left on it. 

To keep the surface of an oilstone flat and even simply, requires 
care in using. Tools should be sharpened on the edge of a stone as 
weU as in the middle to prevent wearing down unevenly, and the 
stone should be turned end for end occasionally. 

To restore an even, flat surface grind the oilstone on the side of a 
grindstone or rub it down with sandstone or an emery brick. 

To prevent an oilstone from glazing requires merely the proper 
use of oil or water. 

The purpose of using either oil or water on a sharpening stone is 
to float the particles of steel that are cut away from the tool, thus 
preventing them from fiUing in between the crystals and causing the 
stone to glaze. 

AU coarse-grained natural stones should be used with water. Use 
plenty of it. 

On medium and fine-grained natural stones and in all artificial 
stones, oil should be used always, as water is not thick enough to 
keep the steel out of the pores. 

To finrther prevent glazing, the dirty oil should always he wiped 
off the stone thoroughly as soon as possible after using it. This is 
very important, for if left on the stone, the oil dries in, carrying the 
steel dust with it. Cotton waste is one of the best things to clean a 
stone with, and is nearly always to be found in a shop. 

If the stone does become glazed or gummed up, a good cleaning 
with gasolene or ammonia will usuaUy restore its cutting qualities, but 
if it does not, then scour the stone with loose emery or sandpaper 
fastened to a perfectly smooth board. 

Never use turpentine on an oilstone for any purpose. 



SCREW MACHINE TOOLS, SPEEDS 
AND FEEDS 



BOX TOOLS AND CUTTERS 

The general principles of two types of box tools using respectively 
tangent and radial cutters are represented in Figs, i and 2. The 
former type is generally used for roughing and the latter for finishing. 
The tangent cutter in the type of box tool shown in Fig. i lies in a 
slot formed parallel to the bottom of the box but at an angle, usually 



Cutter 




Fig. 



■Roughing Box Tool with 
Tangent Cutter 



cen degrees, with the front of the box, thus giving the desired rake 
at the cutting point. Finishing cutters of the type in Fig. 2 are 
Straight on the end, located square with the work and ordinarily 
ground as indicated to give 7 to 10 degrees front clearance for steel 
and 5 to 8 degrees for brass. 

The tangent cutter is sharpened by grinding on the end, and com- 
pensation for the grindii:g away of the metal is made by adjusting 
the cutter forward, v/hereas in the radial type of cutter in Fig. 2, 
frequent sharpening cannot be done without resulting in lowering 
the cutting edge of the tool below the center of the work, unless a 
substantial part of the tool be sacrificed. The radial tool, however, 
is easily ground accurately on face a, which is the edge gover'aing the 
finish; while the corresponding face on the tangent tool is rather 
difficult to grind so as to produce as smooth work. 

24s 



246 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 

The sizes of steel recommended for box-tool cutters are as follows: 
For box tools used for stock diameters up to jV inch, i\ inch square; 
up to f inch diameter, 3% inch square; ujf to J inch diameter, \ inch 
square; up to f inch diameter, y\ inch square; up to i inch diameter, 
f inch square; up to ij inches diameter, J inch square. 

HOLLOW MILLS 

The teeth of hollow mills should be radial or ahead of the center. 
With the cutting edge ahead of the center, as in Fig. 3, the chips as 
produced are caused to move outward away from the work and pre- 
vented from disfiguring it. With the cutting edge below the center, 
rough turning will result. With the cutting edge greatly above the 
center, chattering occurs. About one tenth of the cutting diameter 
is a good average amount to cut tlie teeth ahead of the center. 




7° to 10 for Steel 
5° to 8°for Brass 



Fig. 2. — Finishing Box Tool with 
Radial Cutter 



When the chips produced from any turning or boring cut cur! 
nicely, it is indicative of a free cutting action; but these chips are 
very troublesome on the automatic screw machine. In making hollow- 
mills for the automatic, part or all of the rake to the cutting edge is 
generally sacrificed. 

The table under the hollow mill in Fig. 3 gives proportions of 
mills from xV to f diameter, showing the amount to cut the teeth 
ahead of the center, the taper of the hole, etc. 



DIES AND TAPS 



247 




D = 


■ Finishing. . "1 
. Roughing . J 


.072 


.104 


•135 


.166 


ft 
.197 


.229 


.26 


.291 


ft 
.322 


1 
•385 


.510 


1 
635 


f 

.760 




L = 


i 


i 


^ 


T^S 


f 


1 


ft 


ft 


4 


f 


1 


i- 


I 




10 


.006 


.009 


.012 


.015 


.019 


.022 


.025 


.028 


•031 


.038 


.050 


.063 


.075 




I = 


1% 


fs 


fs 


A- 


ft 


1 


f 


i 


1 


ft 


ft 


H 


ii 




= 


1 


1 


1 


t 


1 


f 


f 


1 


1 


I 


i\ 


If 


if 



Fig. 3. — Hollow Mill Dimensions 



DIES AND TAPS 

It is good practice in making spring screw dies to either hob out 
the thread with a hob tap 0.005 to 0.015 i^ch over-size, according 
to size, and in use to spring the prongs to proper cutting size by a 
clamping ring, or to tap the die out from the rear with a hob tap 
tapering from y^g inch to J inch per foot, leaving the front end about 
0.002 inch over cutting size, and in this case also to use a clamping 
ring. Both of these schemes are for the purpose of obtaining back 
clearance and are effective. Of the two the use of the taper hob is 
to be preferred. 



248 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 

Spring Die Sizes 

The table of dimensions for spring screw dies, Fig. 4, should proye 
of service, particularly for steel. For brass the cutting edge is 
radial, thus eliminating dimension A. The width of land at bottom 
of thread is usually made about j outside diameter of cut, the milling 
between flutes being 70 degrees, leaving 50 degrees for the prong in 
the case of three-flute dies. 



Taper of Tap=H per Ft. 




Small Sizes of Dies 
(Over all Dimensions Given in Sketch) 



D = 


rV 


f 


A 


i 


A 


No. 
3 


4 


6 


8 


10 


12 


Threads P. I. = 

10 


64 

.003 


40 
.012 


32 

.019 


20 

.025 


18 
.031 


56 
.010 


40 
.011 


32 
.014 


24- 

32 

.016 


24- 

32 

0.19 


24- 

32 

.021 


L = 


t\ 


3^ 


f 


h 


i 


aV 


i 


3^. 


t\ 


H 


f 



Sizes | to 1 Inch 



D = 


ftoi 


Hof 


f to I 


Th' s P.I. = 


Std. 


Std. 


Std. 


A = 


D ^ ID 


D ^ 10 


D ^ 10 


L = 


f 


x" 


li 


O.S. Dia. 


I" 


li 


if 


Length 


2" 


2^ 


2Y 



Fig. 4. — Spring Die Dimensions 

Sizing Work for Threading 

In boring holes previously to tapping they should be somewhat 
larger than the theoretical diameter at bottom of thread, as the 
crowding action of the tap will cause the metal to flow som^e and 
compensate for this. Where no allowance is made, frequent tap 
breakage is liable to occur and torn threads in the work also. On 



TAP LENGTH AND NUMBER OF LANDS 



249 



external work it is for the same reasons advisable to turn the work 
undersize and the following table gives good average allowances for 
both internal and external work. 

Allowances for Threading in the Screw Machine 



Threads 
per Inch 


External Work 
Turn Undersize 


Internal Work 

Increase Over Theoretical 

Bottom of Thread 


28 


0.002 


0.004 


24 


0.002 


0.0045 


22 


0.0025 


0.005 


20 


0.0025 


0.0055 


16 


0.003 


0.006 


14 


0.003 


0.0065 


13 


0.0035 


0.007 


. 12 


0.0035 


0.007 


II 


0.0035 


0.0075 


ID 


0.004 


0.008 


9 


0.004 


0.0085 


8 


0.0045 


0.009 


7 


0.0045 


0.0095 


6 


0.005 


O.OIO 



Tap Length and Number of Lands 

The number of teeth in taps and the width of land should be 
regulated by the diameter and pitch of work as well as the nature of 
the material being cut. On fine threads, where a drunken thread is 
to be insured against, more teeth are required than on a coarser pitch 
of the same diameter. A good average number of teeth on taps for 
United States standard threads is given in the following table. With 



Outside Dia. 


No. of Flutes 


Width of Land 


A 


4 


6^ 


i 


4 


tV 


t\ 


4 




f 


4 


J^ 


T^ 


4 


i-i 


^ 


4 


i 


f 


4 


'h 


f 


4 




i 


4 


3V 


I 


4 


i 


li 


4 


A 



too few teeth and too short land very little support is afforded and 
this may cause chattering; too much land in contact causes heat due 
to excessive friction, welding of chips and torn threads. 



250 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 



^^'' 


/ / 
/ / 


ff 
tt 




// 






// 


i 
1 *^ 
•0 




// 


1 


\ 


/ / 


ix. 



^ 




FORMING TOOLS 



251 



FORMING TOOLS 

The two types of forming cutters commonly used in the screw 
machine are shown in Figs. 5 and 6. The circular forming cutter in 
Fig. 5 is usually cut away from J to -^^ inch below center to give 
suitable cutting clearance and the center of the tool post on which 
it is mounted is a corresponding amount above the center of the 
machine, so that the cutting edge of the circular tool is brought on 




Fig. 5. — Circular Forming Tool 

the center line of the work. The relative clearance ordinarily 
obtained by circular cutters and dovetail tools of the type shown in 
Fig. 6, is indicated in Fig. 7. It is obvious that with a given material 
the larger the diameter of the work the greater the angle of clearance 
required. Clearance angles are seldom less than 7 degrees or over 
12 degrees. 

The diameter of circular forming tools is an important matter for 
consideration. A small diameter has a more pronounced change of 



t 




Fig. 6. — Dovetail Forming Tool 

clearance angle than a large diameter. In fact, when of an exceed- 
ingly large diameter the circular tool approaches in cutting action 
the dovetail type of tool which is usually provided with about 10 
degrees clearance. Circular tools usually range from about if to 
3 inches diameter, depending upon the size of machine in which 
they are used. 



252 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 



Getting the Tool Diameters at Different Points 

In order to make a circular or a dovetail type of tool so that 
the contour of its cutting edge is such as to produce correct work, the 
amount a circular tool is cut below center, as at c in Fig, 8, and the 
clearance angle of a dovetail tool as at A' , Fig. 7 must be known. 
Thus, referring to Fig. 8, the forming tool shown cuts two dififerent 
diameters on the work, the step between being represented by dimen- 
sion a. To find -depth / to which the forming tool must be finished 
on the cent^ line to give the correct depth of cut a in the work (the 




Tool cut out here 
after Forming 



To suit amount Auto- 
matic Tool Holder is" 
above Center. 



Master Tool 



Fig. 10. — Finishing a Circular Tool 



cutter being milled below center an amount represented by c) the 
following formula may be applied: 



Suppose the depth of cut in the work represented by o to be 0.152'; 
the radius g of the forming cutter i inch; the distance c which the 
forming tool is milled below center, x\ inch. Applying the above 
formula to find/ and substituting the values just given for the letters 

in the formula we have/ = i— Vi + .0231 - (.304 \/i — • 03516) 
= I - V I + .02 31 - (.304 X .9823) 
= I - \/ .724485 = I — .8512 = .1488 
Then/ =.1488 



DOVETAIL TOOL DEPTHS 



253 



Dovetail Tool Depths 

If a similar piece of work is to be formed with a dovetail type of 
cutter, the distance T, Figs. 7 and 9, to which it is necessary to plane 
the tool shoulder in order that it may cut depth a correctly in the 
work, is found by the formula: T = a (cosine A'). As 10 degrees 
is the customary clearance on this form of tool, the cosine of this 
angle, which is .98481, may be considered a constant, making refer- 
ence to a table of cosines unnecessary as a rule. Assuming the same 
depth for a as in the previous case, that is .152 inch, and multiplying 
by .98481, gives .1496 inch as the depth of T to which the tool must 
be planed. 



Dovetail 
Cutter Blank 




Fig. II. — Finishing a Dovetail Forming Tool 



While it frequently is necessary or advisable to determine by 
calculation the dimension computed in the preceding examples, in 
the majority of cases when making a cutter with a master tool of 
the same outline as the model, the correct form in the circular cutter 
is obtained automatically by dropping the master tool to the same 
distance below the lathe center as the circular cutter is to be milled 
off center and then feeding it in to finish the cutter. This procedure, 
shown in Fig. 10, assures the correct shape at all points being pro- 
duced on the exact working plane of the cutter. Similarly, in finish- 
ing a dovetail cutter in the planer or shaper, the master tool may be 
set as in Fig. 11 at the same angle with the cutter (usually 10 degrees) 
as the latter will afterward be applied to the work. 



254 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 



CIRCULAR TOOL FOR CONICAL POINTS 

When a circular cutter is to be mad^ for forming a conical surface* 
on a piece as in Fig. 1 2, a master tool of the exact angle required on 
the work may be used for finishing the cutter in the same way as the 
tool in Fig. 9 is applied; that is, the master is to be dropped below 
center the amount the cutter center is to be above the work center 
when in operation. The distance is represented by A in Fig. 12. 
Another method, which avoids the necessity of making a master tool, 
is to set the compound rest of the lathe to the exact angle required 
(in this case 30 degrees with the center line) and with a horizontal 




Fig. 12. — Circular Forming Tool for Conical Points 



cutting tool set at distance D below center, turn off one side of the 
cutter blank and then set the compound rest around the other way 
and face off the other side. If desired a similar method may be 
followed for grinding the forming cutter after hardening. The 
arbor carrying the cutter should be located either above or below 

the grinding wheel a distance equal to D where D equals 

the depth the cutter is milled below center, r the radius of the cutter, 
and R the radius of the emery wheel. Assuming D to be .187 (y^g) 
inch; R, 2.5 inches; and r, i inch, the vertical distance between centers 

of forming tool and grinding wheel centers would equal .187 '— 

= .187 (3.5) = .6562 (fl) inch. 



DIAMETERS OF FORMING TOOLS 



255 



FINDING DIAMETERS OF CIRCULAR 
FORMING TOOLS 

In making circular forming tools it is oftentimes desirable to check 
the finished tool or finish a tool by grinding. It may also be advan- 
tageous to know the exact diameter a tool should be turned while 
making it, in order that calipering may be more convenient and 
certain. Methods of computing the diameter at different points are 
given on page 252, but in many cases of this kind the following 
tables win greatly facilitate matters, particularly when making 
circular forming tools for 
Brown & Sharpe automatic 
screw machines: 

Suppose, for example, we 
have a piece to make hke Fig. 
13, on the No. 2 BrouTi & 
Sharpe automatic screw ma- 
chine. The largest diameter 
of the circular forming tool 
would produce the smallest 

diameter of the piece, which is 0.250 inch. The difference between 
this 0.250-inch diameter and the step of the 0.750-inch diameter 
is (0.750 — 0.250 inch) -r- 2 = 0.250 inch. 

The largest diameter of the circular forming tool for the No. 2 
machine is 3 inches, which corresponds to a radius of 1.49998 inches 
with a base Hne of 1.479 ii^ch for the triangle completed by the per- 
pendicular joining the cutting line of the tool with the parallel line 
passing through the center of the tool. 

The h>Tpothenuse of the triangle is formed by the radius joining 
the intersection of the base line and the circumference of the tool 
as in Fig. 14. Subtracting 0.250 inch from 1.479 inches we have 
1.229 inches, which, in Table 4, corresponds to a radius of i. 2541 7 
inches, and multiplying by 2 gives a diameter of 2.50834 inches, 
to which to turn the cutter to correctly form the 0.750-inch diameter 
on the piece. Fig. 13. 

Considering the largest diameter of the piece and taking the height 




The piece to be made 



of the second step above the first diameter, we have 



0.938 — 0.25 



0.344 inch, and subtracting from 1.479 = 1.135 for the base line, 
which, in Table 4, corresponds to a radius of 1.16221. Multiplying 
by 2 gives a diameter of 2.3244 to turn the cutter to in order to pro- 
duce the 0.938-inch diameter on the work. Tables 2, 3 and 4 are 
for cutters of the dimensions given in Table i. 

These tables are figured in steps of 0.00 1 inch for the capacity of 
the machines. A difference of a fractional part of a thousandth can 
be added to the radius if the step is a part of a thousandth over the 
base-line figures, which are given in even thousandths. For illus- 
tration: Say the base-line figure is 1.4765 inches. In the table 
1.476 inches corresponds to a radius of 1.49702; add 0.0005 inch to 
1.49702 and the radius will be as near correct as it is practicable to 
make a cutter. 



256 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 




Table i. — Dimensions of Cutters for 
B. & S. Automatic Screw Machines 



Mach. 
No. 


Approx. 
Diam. 


Max. 
Radius 


Max. 
Base Line 


Distance Above 
or Below Center 


2 



00 


% 


1.49998" 
1. 1 2474" 
0.87497" 


1.479" 
1. 109" 
0.866" 


0.250" 

0.1875" 

0.125" 



Fig. 14 



Table 2, — For Finding Diameters of Circular Forming Tools 
FOR Brown & Sharpe No. 00 Automatic Screw Machine 



No. 00 


No. 00 


No. 00 


No. 00 


No. 00 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


.866 
.865 
.864 
.863 
.862 
.861 
.860 

i% 

.857 
.856 
.855 
■854 

.853 
.852 
.851 
.850 

'.sis 

.847 
.846 
.845 
.844 
.843 
.842 


.87497 
.87398 
•87300 
.87201 
.S7102 
.87003 
.86904 
.86805 
.86706 
.86607 
.86508 
.86409 
.86310 
.86211 
.86112 
.86013 
.85914 
.85815 
.85716 
.85617 
.85518 
.85420 
.85321 
.S5222 
•85123 


.841 
.840 

i% 

.837 
.836 
.835 
.834 
•833 
.832 
.831 
.830 
.829 
.828 
.827 
.826 
•825 
.824 
.823 
.822 
.S21 
.8 20 
.819 
.81S 
.817 
.816 


.85024 
.84925 
.84826 
•84727 
.84628 
•84529 
•84430 
•84332 
•84233 
.84134 
•84035 
•83936 
•83837 
•83738 
•83639 
.83540 
.83442 
•83343 
•83244 
•83145 
.83046 

fi% 

•82750 
.82651 
.82552 


.S15 
.814 
•813 
.812 
.811 
.810 

^807 
.806 
.805 
.804 
.803 
.802 
.801 
.800 
•799 
•798 
•797 
•796 
•795 
•794 
•793 

• 792 
.791 

• 790 




82453 
82354 
82255 
S2156 
S2058 

81761 
81662 
81564 
81465 
S1366 
81267 
81168 
81069 
80971 
80872 
80773 
80674 
80576 
80477 
80378 
80279 
80180 
80082 
79983 


■.788 
•787 
.786 
•785 

• 784 

• 783 
.782 
.781 
.780 

■III 

•777 

• 776 
•775 
.774 
•773 

• 772 
.771 
.770 

'.768 

• 767 
.766 
.765 
.764 


.79884 
•79785 
.79686 
.79588 
•79489 
•79390 
•79291 
•79193 
•79094 

•78798 
.78699 

.78600 
.78502 
.78403 
•78304 

.78205 
.78107 
.78008 
•77909 
•778II 
•77712 
•77613 

•77515 

•77416 


.763 
.762 
.761 
.760 
•759 
.758 
•757 
•756 
■755 
•754 

• 753 
•752 
•751 

• 750 
-749 
•748 
.747 
.746 
•745 
■744 
•743 
•742 
.741 
•740 


.77317 
.77218 
.77120 
.77021 
.76922 
.76823 
.76725 
.76626 
.76528 
.76429 
.76330 
.76232 
•76133 
.76035 
•75936 
.75837 
•75739 
•75640 
•75541 
.75443 
•75344 
.75246 
•75147 
.75048 



Note. — In the above Table 2 and Tables 3 and 4, it should be 
noted, as explained on page 255, that the Base Line dimensions in 
the columns under that heading and in the diagram, Fig. 14, are 
actually the distance of the cutting edge of the tool from the center 
oi the cutter, the latter being used in the machine a certain distance 
either above or below the spindle center corresponding to Table i. 
The distance from the cutting edge to center is therefore shorter 
than the true cutter radius by the amount indicated in the tables. 



DIAMETERS OF FORMING TOOLS 



257 



Table 3. — For Finding Diameters of Circular Forming 

Tools for Brown & Sharpe No. o Automatic 

Screw Machine 



No. 


No.o 


No.o 


No.o 


IS 


0. 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


Bnsp 
Line 


Radius 


Base 
Line 


Radius 


1. 109 


1. 12474 


1.060 


1.07646 


1. 010 


1.02726 


.960 


•97813 


.910 


.92911 


1. 108 


I-I237S 


i.059 


1.07547 


1.009 


1.02627 


•959 


•97715 


.909 


•92813 


1. 107 


1. 12277 


1.058 


1.07448 


1.008 


1.02529 


•958 


•97617 


.908 


■9271S 


1. 106 


1.12178 


1.057 


1.07350 


1.007 


1.02431 


•957 


•97519 


.907 


.92617 


1. 105 


1. 12079 


1.056 


1.07252 


1.006 


1.02332 


•956 


.97421 


.906 


.92519 


1. 104 


1.11981 


1.055 


1.07153 


1.005 


1.02234 


•955 


•97323 


.905 


.92421 


1. 103 


1.11882 


1.054 


1.07055 


1.004 


1. 02136 


•954 


.97225 


.904 


.92324 


1. 102 


1.11784 


I-OS3 


1.06956 


1.003 


1.02038 


•953 


.97127 


.903 


.92226 


I.IOI 


1.11685 


1.052 


1.06857 


1.002 


1.01939 


•952 


.97028 


.902 


.92128 


1. 100 


1.11586 


1.051 


1.06759 


I.OOI 


1.01841 


•951 


.96930 


.901 


.92030 


1.099 


1.11488 


1.050 


1.06661 


1. 000 


1.01743 


•950 


.96832 


.900 


.91932 


1.098 


1.11389 


1.049 


1.06563 


.999 


1.01644 


•949 


.96734 


.899 


.91834 


1.097 


1.11291 


1.048 


1.06464 


.998 


1.01546 


•948 


.96636 


.898 


.91732 


i.oq6 


1.11192 


1.047 


1.06366 


.997 


1.01448 


•947 


.96538 


.897 


.91638 


1.095 


1. 1 1094 


1.046 


1.06267 


.996 


1.01349 


•946 


.96440 


.896 


.91540 


1.094 


1. 10995 


1 .045 


1. 06 1 69 


.995 


1.01251 


.945 


.96342 


.895 


.91442 


1.093 


1. 10896 


1.044 


1.06070 


.994 


1.01153 


•944 


.96244 


.894 


•9134s 


1.092 


1. 10798 


1.043 


1.05972 


•993 


1.01055 


•943 


.96146 


■893 


.91247 


1. 09 1 


1. 10699 


1.042 


1.05874 


.992 


1.00957 


•942 


.96047 


.892 


.91149 


1.090 


1.10601 


1. 041 


1.05775 


.991 


1.00858 


.941 


.95949 


.891 


•91051 


1.089 


I. 10502 


1.040 


1.05677 


•990 


1.00760 


•940 


.95851 


.890 


•90953 


1.088 


1. 10404 


1.039 


1.05578 


.989 


1.00662 


•939 


•95753 


.889 


•9085s 


1.087 


1. 10305 


1.038 


1.05480 


.988 


1.00563 


•938 


•95655 


.888 


•90757 


1.086 


1. 10207 


1.037 


1.05381 


.987 


1.00465 


•937 


•95557 


.887 


.90660 


i.oSs 


1.10108 


1.036 


1.05283 


.986 


1.00367 


.936 


-95459 


.886 


.90562 


1.084 


1. 10009 


1.035 


1.05185 


.985 


1.00269 


•935 


•95361 


.885 


.90464 


1.083 


1. 099 1 1 


I.034 


1.05086 


.984 


1.00170 


•934 


•95263 


.884 


.90366 


1.082 


1.09813 


1.033 


1,04988 


.983 


1.00072 


•933 


•95165 


.883 


.90268 


1. 08 1 


1.09714 


1.032 


1.04889 


.982 


.99974 


•932 


-95067 


.882 


.90170 


1.080 


1.09616 


1.031 


1.04791 


.981 


.99875 


•931 


.94969 


.881 


•90073 


1.079 


1. 095 1 7 


1.030 


1.04693 


.980 


•99777 


•930 


•94871 


.880 


•89975 


1.078 


1. 094 1 8 


1.029 


1.04594 


.979 


•99679 


•929 


•94773 


.879 


.89877 


1.077 


1.09319 


1.028 


1.04496 


.978 


•99581 


.928 


•94675 


.878 


.89779 


1.076 


1.09221 


1.027 


1.04398 


.977 


•99483 


•927 


•94577 


.877 


.89681 


I-07S 


1.09123 


1.026 


1.04299 


.976 


•99384 


.926 


•94479 


.876 


.89584 


1.074 


1.09024 


1.025 


1.04200 


•975 


.99286 


•925 


•94381 


.875 


.89486 


1.073 




1.024 


1. 04102 


.974 


.99188 


.924 


.94283 


.874 


.89388 


1.072 


1.08828 


1.023 


1.04004 


.973 


.99090 


•923 


.94185 


.873 


.89290 


1. 071 


1.08729 


1.022 


1.03906 


.972 


.98991 


.922 


.94087 


.872 


.89193 


1.070 


1.08630 


1.02 1 


1.03807 


.971 


.98893 


.921 


.93989 


.871 


.89095 


1.069 


1.08532 


1.020 


1.03709 


.970 


•98795 


.920 


.93891 


.870 


.88997 


1.068 


1.08433 


1. 019 


1.03611 


.969 


.98697 


•919 


.93793 


.869 


.88899 


1.067 


1-08335 


1.018 


1.03512 


.968 


•98559 


.918 


.93695 


.868 


.88802 


1.066 


1.08236 


1. 017 


1. 03414 


.967 


.98501 


.917 


.93597 


.867 


.88704 


1.065 


1.08138 


1. 016 


1.03316 


.966 


.98402 


.916 


.93499 


.866 


.88607 


1.064 


1.08039 


1.015 


1.03217 


.965 


•98304 


•915 


.93401 


.865 


.88508 


1.063 


1.07941 


1.014 


1.03119 


.964 


.98206 


.914 


.93303 


.864 


.88411 


1.062 


1.07842 


1.013 


1.0302 I 


.963 


.98108 


.913 


•93205 


.863 


.88313 


1. 06 1 


1.07744 


1.012 


1.02922 


.962 


.98010 


.912 


.93107 


.862 


.88216 






I. on 


1.02824 


.961 


•97912 


.911 


■93009 


.86i 
.860 
•859 


.88118 
.88020 
.87922 



258 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 



Table 4. — For Finding Diameters of Circular Forming 

Tools tor Brov/n & Sharpe No. 2 Automatic 

Screw Machine 



No. 2 


No. 


2 


No. 


2 


No. 


2 


No. 2 


Base 
Line 


Radius j 


ase T 
.ine 


laclius T 


ase ^ 


adius j- 


ase p 
.ine ^ 


adius 


Base 
Line 


Radius 


1.479 


1.49998 I 


430 I 


45168 I 


380 1 


40246 I 


330 I 


35329 


1.280 


1.30419 


1.478 


1.49899 I 


429 I 


45070 I 


379 I 


40148 I 


329 I 


35231 


1.279 


1.30320 


1-477 


1. 49801 I 


428 1 


44982 I 


378 I 


40050 I 


328 1 


35133 


1.278 


1.30222 


1.476 


1.49702 I 


427 I 


44873 I 


377 I 


39952 I 


327 I 


35035 


1.277 


1.30124 


1-475 


1.49604 I 


426 I 


44775 I 


376 I 


39853 I 


326 1 


34936 


1.276 


1.30026 


1.474 


1-49505 I 


425 I 


44676 I 


375 I 


39754 I 


32s I 


34838 


1-275 


1.29928 


1-473 


1.49406 I 


424 I 


44578 I 


374 I 


39656 . I 


324 I 


34740 


1.274 


1.29830 


1.472 


1.49308 I 


423 I 


44479 I 


373 I 


39558 I 


323 I 


34641 


1.273 


1-29732 


1.471 


1.49209 I 


422 I 


44381 I 


372 I 


39459 I 


322 I 


34543 


1.272 


1.29633 


1.470 


1.49110 I 


421 I 


44282 I 


371 I 


39360 I 


321 1 


34445 


1.271 


I-2953S 


1.46Q 


1. 4901 2 I 


420 I 


441 84 I 


370 I 


39262 I 


320 I 


34347 


1.270 


1.29437 


1.468 


1.48913 I 


419 I 


44085 I 


369 I 


39164 I 


319 I 


34248 


1.269 


1-29339 


1.467 


1.48815 I 


418 I 


43987 I 


368 I 


39066 I 


318 1 


34150 


1.268 


1. 29241 


1.466 


1.48716 I 


417 I 


43874 I 


367 I 


38967 I 


317 I 


34052 


1.267 


1.29143 


1.46s 


1.48618 I 


416 I 


43790 I 


366 I 


38869 I 


316 I 


33954 


1.266 


1.29045 


1.464 


1.48519 I 


415 I 


43090 I 


365 I 


38770 I 


315 I 


3385s 


1.265 


1.28947 


1.463 


1. 4842 1 I 


414 I 


43593 I 


364 I 


38672 I 


314 I 


337S7 


1.264 


1.28848 


1.462 


1.48322 I 


413 I 


43495 I 


363 I 


38574 I 


313 I 


33659 


1.263 


1.28750 


1.461 


1.48223 I 


412 I 


43396 I 


362 I 


38475 I 


312 I 


33560 


1.262 


1.28652 


1.460 


1.4812s I 


411 I 


43298 I 


361 I 


38377 I 


311 I 


33462 


1. 261 


1-28554 


1-459 


1.48026 I 


410 I 


43199 I 


360 I 


38279 I 


310 I 


33364 


1.260 


1.28456 


1.458 


1.47928 I 


409 I 


43100 I 


359 I 


38181 I 


309 I 


33266 


1-259 


1-28358 


1-457 


1.47829 I 


408 I 


43002 I 


358 I 


38082 I 


30S I 


33168 


1-258 


1.28260 


1.456 


1.47731 I 


407 I 


42905 I 


357 I 


37984 I 


307 I 


33069 


1-257 


i;28i62 


1.455 


1.47632 I 


406 I 


42805 I 


356 I 


3788s I 


306 I 


32971 


1.256 


1.28064 


1-454 


1-47534 I 


405 I 


42707 I 


355 I 


37786 I 


305 I 


32873 


1-255 


1.27966 


1-453 


1-47435 I 


404 I 


42608 I 


354 I 


37689 I 


304 I 


32775 


1.254 


1.27868 


1.452 


1-47337 I 


403 I 


42510 I 


353 I 


37590 I 


303 I 


32677 


1.253 


1.27770 


I-45I 


1-47238 I 


402 I 


42411 I 


352 I 


37492 I 


302 1 


32578 


1-252 


1.27672 


1.450 


1.47139 I 


401 I 


42313 I 


351 I 


37393 I 


301 1 


32480 


1-251 


1-27574 


1.449 


1.47041 I 


400 I 


42215 I 


350 I 


37295 I 


300 I 


32382 


1.250 


1.27476 


1.448 


1.46944 I 


399 I 


42116 I 


349 I 


37197 I 


299 I 


32284 


1.249 


1.27377 


1-447 


1.46846 I 


398 I 


42118 I 


348 I 


37098 I 


298 I 


32186 


1.248 


1.27279 


1.446 


1.46745 I 


397 I 


41919 I 


347 I 


37000 I 


297 I 


32087 


1.247 


1.27181 


1-445 


1.46647 I 


396 I 


41821 I 


346 I 


36902 I 


296 I 


31989 


1.246 


1.27083 


1.444 


1.46548 I 


395 I 


41723 I 


345 I 


36S04 I 


295 I 


31891 


1-245 


1.26985 


1-443 


1.46459 I 


394 I 


41624 I 


344 I 


36705 I 


294 I 


31793 


1.244 


1.26887 


1.442 


1.46351 I 


393 I 


41526 I 


343 I 


36607 I 


293 I 


31695 


1-243 


1.26789 


1.441 


1.46253 I 


392 I 


41427 I 


342 I 


36509 I 


292 I 


31596 


1.242 


1. 26691 


1.440 


1.46154 I 


391 I 


41329 I 


341 I 


36410 I 


291 1 


31498 


1.241 


1-26593 


1-439 


1.46056 I 


390 I 


41230 I 


340 I 


36312 I 


290 I 


31400 


1.240 


1-26495 


1.438 


I-459S7 I 


389 I 


41132 I 


339 I 


36214 I 


289 I 


3 130 1 


1.239 


1.26397 


1-437 


1-45853 I 


388 I 


41033 I 


338 I 


36116 I 


288 I 


31203 


1.238 


1.26299 


1.436 


1-45759 I 


387 I 


40935 I 


337 I 


36017 I 


287 I 


31x06 


1.237 


1.26201 


1-435 


1.45661 I 


386 I 


40837 I 


336 I 


35919 I 


286 1 


31008 


1-236 


1. 26103 


1-434 


1-45563 I 


385 I 


40738 I 


335 I 


35820 I 


28s I 


30909 


1-235 


1. 2 6005 


1-433 


1.45464 I 


384 I 


40640 I 


334 I 


35722 I 


284 1 


30811 


1-234 


1-25907 


1.432 


1.45366 I 


383 I 


40541 I 


333 I 


35624 1 


283 1 


30713 


1-233 


1.25809 


1.43 1 


1.45267 I 


382 I 


40443 I 


332 I 


35526 1 


282 1 


3061S 


1-232 


1.25711 






381 I 


40345 I 


331 I 


35428 I 


281 1 


30517 


I-231 


1.25613 



DIAMETERS OF FORMING TOOLS 



259 



Table 4. — For Finding Diameters of Circular Forming 

Tools for Brown & Sharpe No. 2 Automatic " 

Screw Machine 



No. 2 


No. 2 


No. 2 


No. 2 


No. 2 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


Base 
Line 


Radius 


1.230 


1-25515 


1.178 


1.20424 


1.126 


1.15342 


1.074 


1. 10271 


1.022 


1-05213 


1.229 


I. 25417 


1. 177 


1.20326 


1.125 


1.15244 


1.073 


1.10174 


1.021 


1.05116 


1.228 


1-25319 


1.176 


1.20228 


1.124 


1-15147 


1.072 


1.10076 


1.020 


1-05019 


1.227 


I. 25221 


1-175 


1.20130 


1.123 


1.15049 


1.071 


1.09979 


1.019 


1.04920 


1.226 


I. 25123 


1.174 


1.20032 


1.122 


1.14951 


1.070 


1.09882 


1.018 


1.04825 


1. 225 


1.25025 


I-I73 


1.19934 


1. 121 


1-14854 


1.069 


1.09784 


1.017 


1.04728 


1.224 


1.24927 


1.172 


1.19837 


1.120 


1.14756 


1.068 


1.09687 


1.016 


1.04631 


1.223 


1.24829 


1. 171 


I-I9739 


1.119 


1.14659 


1.067 


1.09590 


1.015 


I-04S33 


1.222 


I. 24731 


1.170 


1.19641 


1.118 


1.14561 


1.066 


1.09492 


1.014 


1.04436 


1. 221 


1-24633 


1.169 


I-19543 


1.117 


1.14463 


1.065 


1-09395 


1.013 


1-04339 


1.220 


1-24535 


1.168 


1.19446 


1.116 


1.14366 


1.064 


1.09298 


1.012 


1.04242 


1. 219 


1-24437 


1.167 


I-19348 


1-115 


1.14268 


1.063 


1.09200 


1.011 


1.0414S 


1. 218 


1-24339 


1.166 


1.19250 


1.114 


1. 14171 


1.062 


1.09103 


l.OIO 


1.04048 


1. 217 


1. 24241 


1.165 


1.19152 


1.113 


1.14073 


1.061 


1.09006 


1.009 


1.03951 


I.216 


1. 24143 


1.164 


1.19054 


1.112 


1.13976 


1.060 


1.08908 


1.008 


1-03854 


1. 215 


1.2404s 


1.163 


1. 18957 


1.111 


1.13878 


1.059 


1.08811 


1.007 


1-03757 


I.2I4 


1-23947 


1.162 


1.18859 


I.IIO 


1.13780 


1-058 


1.08714 


1.006 


1.03660 


1. 213 


1.23849 


1.161 


1.18761 


1.109 


1-13683 


1-057 


1.08616 


1-005 


1-03563 


1. 212 


1-23752 


1.160 


1.18663 


1.108 


1.13586 


1.056 


1.08519 


1.004 


1.03466 


1. 211 


1-23654 


I-159 


1.18566 


1. 107 


1.13488 


I 055 


1.08422 


1.003 


1-03369 


1. 210 


1-23556 


1-158 


1. 18468 


1.106 


1. 13390 


1.054 


1.08324 


1.002 


1-03273 


1.209 


1-23458 


I-157 


1-18370 


1.105 


1-13293 


I-053 


1.08227 


l.OOI 


1-03175 


1.208 


1.23360 


1-156 


1. 18272 


1.104 


1-13195 


1.052 


1.08130 


1.000 


1.03078 


1.207 


1.23262 


I-155 


I-18175 


1.103 


1.13098 


1.051 


1.08032 


•999 


1.02981 


1.206 


1. 23164 


1-154 


1.18077 


1.102 


1.13000 


1.050 


1.07935 


.998 


1.02884 


1.205 


1.23066 


I-153 


1.17979 


1.101 


1.12903 


1.049 


1.07838 


.997 


1.02787 


1.204 


1.22968 


1.152 


1.17881 


1. 100 


1.12805 


1.048 


1.07741 


.996 


1.02690 


1.203 


1.22870 


1.151 


1.17784 


1.099 


1.12708 


1.047 


1.07643 


.995 


102593 


1.202 


1.22772 


1.150 


1.17686 


1.098 


1.12610 


1.046 


1.07546 


•994 


1.02496 


1. 201 


1.22675 


1.149 


1.17588 


1.097 


1. 12513 


1.045 


1.07449 


.993 


1-02399 


1.200 


1.22577 


1.148 


1.17491 


1.096 


1-1241S 


1.044 


1-07352 


.992 


1.02302 


1. 199 


1.22479 


1.147 


I-17393 


1.095 


1.12318 


1.043 


1.07254 


.991 


1.02205 


1. 198 


I.22381 


1.146 


1.17295 


1.094 


1.12220 


1.042 


1.07157 


.990 


1.02108 


1. 197 


1.22283 


I-I45 


1-17197 


1.093 


1. 12123 


1.041 


1.07060 


.989 


1.02011 


1. 196 


1. 22185 


1.144 


1.17100 


1.092 


1.12025 


1.040 


1.06963 


.988 


1. 01914 


I-I95 


1.22087 


I -143 


1.17002 


1.091 


1.11928 


1.039 


1.06865 


.987 


1.01817 


1.194 


1. 21989 


1.142 


1.16904 


1.090 


1.11830 


1.038 


1.06768 


.986 


1.01720 


I-I93 


1.21891 


1.141 


1.16807 


1.089 


1-11733 


1.037 


1.06671 


.985 


1.01623 


1. 192 


1. 21793 


1.140 


1.16709 


1.088 


1-11635 


1.036 


1.06574 


•984 


1.01526 


1. 191 


1. 21696 


I-I39 


I. 16612 


1.087 


1-11538 


1035 


1.06477 


•983 


1.01429 


1. 190 


1. 21598 


I-138 


1.16514 


1.086 


1.11440 


1.034 


1.06379 


.982 


1.01332 


1. 189 


1. 21500 


I-137 


1.16416 


1-085 


1-11343 


1-033 


1.06282 


.981 


1.01235 


1. 188 


1. 21402 


1-136 


1.16318 


1.084 


1.11246 


1.032 


1.06185 


.980 


1.01139 


1. 187 


1. 21304 


I-135 


1.16221 


1.083 


1.1114S 


1.031 


1.06088 


•979 


1.01042 


1. 186 


1. 21206 


I-134 


1.16123 


1.082 


1.11051 


1.030 


1.05991 


-978 


1.00945 


1. 185 


1.21108 


I-133 


1.16025 


1.081 


1-10953 


1.029 


105893 


-977 


1.00848 


1. 184 


1.21011 


I-132 


1.15928 


1.080 


1.10856 


1.028 


1.05796 


-976 


1.00751 


I.183 


I. 20913 


I-131 


1-15830 


1.079 


1.10758 


1.027 


1-05699 


•975 


1.00654 


1. 182 


I. 20815 


1-130 


I-15732 


1.078 


1.10661 


1.026 


1.05602 


.974 


1-00557 


I.181 


I. 20717 


1.129 


I-15635 


1.077 


1.10563 


1-025 


1-05505 


•973 


1.00460 


1. 180 


I. 20619 


1.128 


I-I5537 


1.076 


1.10466 


1.024 


1.05408 


.972 


1.00363 


1. 179 


I. 20521 


1. 127 


1.15440 


I.07S 


1.10369 


1.023 


1.05310 


.971 
.970 


1.00267 
1.00170 



26o SCREW MACHINE TOOLS, SPEEDS AND FEEDS 



HARDENING SPRING COLLETS AND FEED CHUCKS 

Before hardening collets it is common practice to open them some- 
what to insure their having a given tension after hardening and 
tempering so that they will open and release the stock the instant 
they are themselves freed by the chucking mechanism. This opening 
of the chuck must be carefully attended to or an eccentric and un- 
satisfactory job will result. Sometimes a simple fLxture having a cone 
pointed spindle is used for this purpose, the collet being held centrally 
while the cone plunger is forced between the chuck jaws to open them 
evenly the necessary amount. No matter how much care is taken in 
this operation, the effect is lost unless the hardening is properly at- 
tended to and only grinding will produce a perfectly true collet. 

Preventing Distortion. — Some toolmakers take the precaution of 
leaving a thin fin of metal at the front end of the collet in each saw 
slot as at ^ , Fig. 1 5, in order that when hardened there shall be no chance 

of distortion due to un- 
equal springing of the 
jaws. This metal tie or 
bridge at the ends of the 
jaws is removed by grind- 
ing out with a thin slitting 
wheel or lap. Another 
method, shown at B, also 
leaves a narrow ring at 
the front end to run on 
grinder center while collet 
is ground outside. The 
^^^- ^5 ring at the end of the nose 

may be ground off leaving the collet ready for use. 

Another method of preventing trouble in hardening is to inserta 
piece of metal, say 3V inch thicker than the width of the saw slot, in 
the front end of the slots and then wire the nose of the chuck tightly 
so as to retain the steel pieces during the hardening process. The 
collet must be heated uniformly and dipped so as to insure all three 
prongs being cooled simultaneously. With the best of care a coUet 
that is hardened but not ground afterward will generally require 
touching up on the conical portion of one or two of the prongs to insure 
its running true. It is not difficult, however, to make the coUet run 
true within 0.002 inch by polishing one or two prongs. 

In order that the collet may close parallel it must be fairly long and 
the outside of each prong or jaw may be relieved by filing so as to 
insure its bearing along the center line on the conical surface. It 
must be carefully tempered at the ends of slots to prevent breaking. 
Feed Chucks. — Feed chucks need no such refinement in their 
production. Thej^ are usually closed after slitting on opposite sides 
so that after hardening they will maintain a constant grip on the 
stock sufficient to feed it forward when it is released by the chuck. 
The idea is indicated at C, Fig. 15. Ordinarily the hole for the stock 
should be bored a little over size otherwise the corners of the feed 
chuck jaws when drawn back over the stock will mar the surface. 




CUTTING SPEEDS AND FEEDS 



261 



Cm 

8 
1 

-it 


1^1 


fg'giiirr 


IM 


10 Ov ro M 0\ t^\0 

0) M M M 


ill 


OOiOiOioOOO 


r°l 




Oh 
5 

u 

w 

u 


IM 


"^ uoO r-- r^ r^ r^oo 

8 8 8 8 8 8 8 8 


IM 


M <N TfOO VO 
<N00 CMOM ONi>. 

10 Tt (N M M M 


^11 




^~»l 


«|00 rHlTJ COH< -hH* r^b^ «|-* 


Oh 

5 

g 

2 


i 




-0 MOO OoOt^Os 

M M LOOO M VO <N 
00 Tj- CS N M H M 


^11 


OiotoioO 


^^1 


rHHCdOOHN"!-* ^ '^'J^"'^ 


Oh 

s 

u 

w 




gfisirii 


> u e 


lOO 0^ rooO to Os (^ 
tJ-C^vO m 100 WOO 

(N M M 




00000000 

00 f^ t^ i>.o ^o ^ 




H«imJ^r-iHK«|<»HMm|-« ^ "^ 



*J 


< 


S 


P>j 


U 


m 


>4 




i^. 


Hi 




to 


^ 


1 


w 


T) 


f^ 








Q 


>-< 


;? 




< 






<D 


rn 




Q 


>^ 


W 


i 






m 










,n 





.=1 


^ 






S! 


[ij 


J3 


p 


(3 


u 






tn 




T) 


<N 






D. 


w 




h-l 






^ 


H 


X 












S^, 












•? 





Oh 

w 

z 


1^^ 


mvotn 




Cj rO M <N '^00 T}- r^. 




OOtOLotoOOO 


6^1 


„,^^.M^,«N^H.-*. 


Oh 

5 
u 
a 


|a| 


q q q q q 




000 invo <N •^00 

000 ^t^lOTtON<N 

c^OOiO-^roc^ W 


^ll 


loiovoo lotoo 


^-1 


c*cH.c^„':i:^trc. 


Ph 
X 

u 

u 
z 


M 


10 vo 10 

^ to^O r^oo c« w 

q q q q 


> ti c 


OOrOTfOO'^Mt^ 
Tt-rot^'^roOoO 0) 
r^OO rncc MD 10 CO ro 


^§ 


OOOioiovDOO 

COCOOO^vOO lOlO 


H 


wH.«ioo^«4^ ^ 'tT'^^'tr 


Oh 
S 

u 

a 
tj 
z 


M 


o" o^'o <^ '-' ^ 
q q q q q 


> u a 

&4 




41 


00000000 

OOOOOOOOCOCOOOOO 


t4 


1 



262 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 



SPEEDS AND FEEDS FOR SCREW MACHINE WORK 

The accompanying tables of speeds and feeds for different types 
of tools used on materials commonly worked in the automatic screw- 
machine have been compiled from data accumulated and thoroughly 
tested during extended experience in this class of work. 

It is, of course, impossible, where a series of tools is used on an 
automatic machine, to select speeds theoretically correct for every 
tool carried by the turret and cross slide. A compromise is necessary 
and therefore speeds are selected which will fall within the range 
suitable for the different tools. 



Speeds and Feeds for Turning 

Tables i and 2, page 261, cover turning speeds and feeds for bright- 
drawn stock (screw stock) and brass, with various depths of chip (that 
is, stock removed on a side) from 3^ up to J inch. These feeds and 
speeds and depths of cut are figured more especially for such tools 



Table 3. Speeds and Feeds for Finish Box Tool 







Screw Stock 




Brass Rod 






-^fc-ii 














c^U 


^ <u 


Feet 


Rev. 


Feed 


Feet 


Rev. 


Feed 




EQo 


Surface 


per 


per 


Surface 


per 


per 


<'Sog 




Speed 


Min. 


Rev. 


Speed 


Min. 


Rev. 




* 


80 


2445 


.0045 


180 


5500 


.0045 


.0025 


tV 


70 


1426 


.0055 


180 


3668 


•0055 


.0025 


i 


6^ 


993 


.0075 


180 


2750 


.0075 


.0045 


^ 


60 


458 


.oil 


180 


1375 


.011 


.006 


1 


60 


305 


.012 


180 


917 


.012 


.006 


I 


60 


229 


.012 


175 


668 


,012 


.0065 


I^ 


55 


140 


.014 


170 


433 


.014 


.007 


2 


50 


95 


.014 


170 


325 


.014 


.008 



With high speed steel tools the above speeds may be increased about 30 per cent 
and feeds 10 to 20 per cent. 

as roughing boxes where the cut, though frequently heavy, is taken 
by a single cutting tool. For a xVi^ich chip the feeds for various 
diameters of stock are practically midway between those tabulated 
for J-and J-inch chips. The feed per revolution for f chip taken on 
diameters ij inch and larger is the same as given for \ inch chip, 
the speed also being the same for corresponding diameters. Where 
hollow mills are used on steel and the work is divided among three 
or more cutting edges the feed per revolution for a given depth of 
chip is about 25 per cent coarser than given for box tools; with both 
classes of tools the feeds are, of course increased as the diameter of 



FEEDS FOR FORMING TOOLS 



263 



the stock increases, the peripheral speeds being reduced as the feeds 
grow coarser. The speeds and feeds for finishing box tools as used 
on screw stock and brass are given in Table 3, the last column indi- 
cating the amount of stock which, generally speaking, it is advisable 
to remove in order to produce a good surface. 

Forming-tool Speeds and Feeds 

Speeds and feeds for forming tools are given in Tables 4 and 5. 
It will be seen that after a work diameter of about J inch has been 
reached, a tool about |-inch wide is adapted to take the coarsest 
feed, tools from this width up to approximately j\ (such as com- 
monly employed for cutting-off purposes) admitting of heavier 
crowding as a rule than either the narrower or wider tools. 

Table 4. Speeds for Forming 



1 


Screw Stock 


Brass Rod 


1 


Screw Stock 


Brass Rod 


Feet 

Surface 
Speed 


Rev. 
per 
Ivlin. 


Feet 
Surface 
Speed 


Rev. 
per 
Alin. 




Feet 
Surface 
Speed 


Rev. 
per 
Min. 


Feet 
Surface 
Speed 


Rev. 
per 
Min. 


t 

f 


75 

75 

70 

65 


2292 

1528 

1069 

662 


200 
200 
185 
185 


6112 

4074 
2827 
1885 


f 
f 

I 


60 
60 
60 
60 


360 

305 
229 

153 


^7S. 
175 
175 
170 


1050 
882 
667 
432 


i 


^5 


497 


185 


1414 


2 


50 


96 


170 


324 


With high speed steel tools the above speeds n 


lay be increased a 


bout 30 per cent. 


Table 5. Feeds for F 


ORMiNG Tools 




Width 


Smallest Diai! 


[ETER OF Form 




of 
Form 








z\ 


1 


JS 


1 


1 


i 


f 


i4 


tV 


.0007 


.0008 


.001 


.0012 


-.0012 


.0012 


.0012 • 


.0012 


i 


.0005 


.0008 


.001 


.OG12 


.0015 


.0020 


.0025 


.0025 


i 




.0007 


.001 


.001 


.0015 


.0015 


.0018 


.0018 


f 






.0009 


.001 


.001 


.0012 


.0015 


.0015 


^ 






.0008 


.0009 


.001 


.001 


.0015 


.0015 


! 








.0008 


.0009 


.001 


.0011 


.0012 


I 










.0008 


.0009 


.001 


.0012 


i^ 










.0007 


.0007 


.0009 


.0011 


2 














.0007 


.001 



With cutting-ofiF tools of high speed steel the above feeds may be increased 10 U 
20 per cent. 



204 SCREW MACHINE TOOLS, SPEEDS AND FEEDS 

Drilling Speeds and Feeds 

Drilling speeds and feeds are given in Table 6. While these 
speeds are based on much higher peripheral velocities than drilU 
makers as a rule recommend for general purposes, it should be 
noted that conditions for drilling in the automatic, on the ordi- 
nary run of work, are usually ideal so far as lubrication, steadi- 
ness of feed, etc., are concerned, and it is possible where the holes 
drilled are comparatively shallow and the drill has ample oppor- 
tunity for cooling during operation of the other tools, to maintain 
speeds that would be considered too high to be attempted in general 
shop practice. 



Table 6. Drilling Feeds and Speeds 




With* high speed drills the above speeds may be increased about 30 per cent. 



Speeds and Feeds for Reaming 

Table 7 is made up of speed and feed data for reamers. In 
this table the feed for different classes of material has been consid- 
ered as constant for any given diameter of reamer, although it is 
probable that with certain materials, especially on brass alloys, etc.. 
the feed per revolution might be increased somewhat, to advantage, 
over the rates given. These feeds have been tabulated, however, as 
representing highly satisfactory practice in reaming the materials 
listed. 



THREADING, COUNTERBORING, ETC. 265 

Table 7, Reaming Feeds and Speeds 



u 






Rev. per Min. 


^ 






Rev. per Min. 


B 


Feed 


Amount 
to 








Feed 


Amount 
to 






a 

V 










CA 


per 


Remove 


Screw 


Brass 


t4 


per 


Remove 


Screw 


Brass 





Rev. 


on 


Stock 


Rod 





Rev. 


on 


Stock 


Rod 


a 




Dia. 


at 


at 


rt 




Dia. 


at 


at 


P 






40 Ft. 


130 Ft. 


Q 






40 Ft. 


1 30 Ft. 


^ 


.005 


.0045 


1222 


3972 


li 


.018 


.010 


122 


397 


t\ 


.006 


.0045 


815 


2648 


I* 


.020 


.010 


102 


331 


i 


.007 


.006 


611 


1986 


If 


.022 


.010 


87 


284 


i 


.0085 


.006 


407 


1324 


2 


.024 


.013 


76 


248 


i 


.0105 


.008 


306 


993 


2i 


.026 


.013 


68 


220 


t 


.012 


.008 


245 


795 


2j 


.028 


.013 


61 


199 


i 


.014 


.008 


204 


662 


2| 


.030 


.013 


56 


181 


I 


.016 


.010 


153 


497 


3 


.032 


.013 


51 


165 



With high speed reamers the above speeds may be increased about 20 per cent 

Threading, Counterboring, Etc. 

Table 8 explains itself and, while giving speeds for threading work 
with dies, should be of equal value in establishing speeds for tapping. 

Table 8. Speeds for Dies. Standard Threads 

WITH high-speed STEEL DIES 





Screw Stock 


Brass Rod 


Si 


Screw 


Stock 


Brass Rod 




















h 










H 













Feet 


Rev. 


Feet 


Rev. 


-K 


Feet 


Rev. 


Feet 


Rev. 


rt 


Surface 


per 


Surface 


per 


ci 


Surface 


per 


Surface 


per 


Q 


Speed 


Min. 


Speed 


Min. 


5 


Speed 


Min. 


Speed 


Min. 


i 


40 


1222 


135 


4126 


f 


35 


178 


115 


586 


i 


40 


611 


125 


1909 


I 


30 


115 


no 


420 


i 


35 


35^ 


120 


1222 


li 


30 


92 


100 


306 


i 


35 


267 


120 


917 


i^ 


30 


76 


90 


229 


t 


35 


210 


120 


715 


2 


25 


48 


85 


162 



For carbon steel dies run at 50 to 75 % of above speeds. 

For feeds for counterbores from f inch to 2 inches diameter, 
Tables i and 2 for turning may be followed where the counterbores 
cut to a depth from one half to three quarters their diameter. Where 
cutting deeper than about one diameter, the feeds should be decreased; 
in such depths it is well to withdraw the counterbore during the 
cutting operation to free it from chips. 



PUNCH PRESS TOOLS 

METHOD OF FINDING THE DIAMETERS OF SHELL 
BLANKS 

This method for the finding of diameters of shell blanks, applies 
also to some other shapes which frequently occur in practice. 

The method is based upon the surface of the shell in comparison 
with the area of the blank and should therefore be used only when 
light material is to be considered. In case of the flanged shapes the 
width of the flange should be small in proportion to the diameter. 

Cylindrical Shell 

Fig. I shows a cylindrical shell of the diameter d and the depth //. 
To find the diameter of the blank, lay down the diameter d of the 
shell twice on a horizontal line, Fig. 2, add to this a distance equal 
to four times the depth h of the shell and describe a semicircle of 
which the total distance is the diameter. The vertical Une D from 
the intersecting point with the circle to the horizontal line gives the 
desired blank diameter. Line D is to be drawn at a distance d from 
the end of the horizontal. 

Flanged Shells 

If the shell has a flange as in Fig. 3, add four times the width of 
this flange to the horizontal line and proceed as above ; see Fig. 4. 

In the case of a hemisphere, Fig. 5, lay down the diameter three 
times on the horizontal hne and draw the vertical line at the dis- 
tance d from the end, as in Fig. 6. 

If the hemisphere has a flange as in Fig. 7, add a distance equal 
to twice the width of the flange to the horizontal line, as in Fig. 8. 
In any case, the length of the vertical line D gives the desired diam- 
eter of blank. 

Taper Shells 

If a shell with tapering sides, Fig. 9, has to be drawn, multiply 
first the bottom diameter by itself and divide the product by the 
sum of the two diameters di and d in order to obtain the length x. 
Otherwise proceed as shown in Fig. 10. 

Flanged Taper Shells 

If the taper shell has a flange of the width a, Fig. 11, add to the 
base line of the diagram twice this width, as shown in Fig. 12. 

266 



DIAMETERS OF SHELL BLANKS 



267 




1 o 






^ — 


T 






II 


^ 


Q 






^ 6 


-Q— > 


-p 




4) 




.L 


"T 


rN^ 


^ 


j^ 


• _i. 


J 


b 






c 




JS 






X" 


5 


1 


_ 








(U 


1 


rC 


C]^ 00 


C/3 




»+-l 








> ta 


12 


' r 


4J 






• 


^ 


? 


S 


.■i_ 


Cj. 



tfe, 




43 d 




268 PUNCH PRESS TOOLS 



TABLE OF DIAMETERS OF SHELL BLANKS 

The table shows the diameters of blanks for shells i x j inch to 
6x6 inches inclusive, by j inches. The figures were obtained by 
the formula given on page 267: 



D = Vc?( d-\- 4 h) 
where, 

d = Diameter of finished shell. 
h = Hight of finished shell. 

They were also checked by figuring on the area of the metal. 
If it is desired to punch the metal in one or more operations, 
get the mean hight of the shell by the following formula; 

ht 
where T 

m = Mean hight of finished shell. 

h = Hight of finished shell. 

t = Thickness of finished shell. 

T = Thickness of metal before drawing. 

Suppose for example, a shell 2 inches diameter by 6 inches high; 
thickness of metal before drawing, 0.040 inch; finish thickness of 
shell, 0.020 inch. Then 

h t 6 X 0.020 . 7 

7n = — = = 3 inches. 

T 0.040 

By using this hight, from the table we find a shell 2 inches diameter 
by 3 inches high requires a blank 5.29 inches diameter. 

When the shell has rounded corners at the bottom, subtract the 
radius of the corner from the figures given in the table. Thus, in 




Fig. 13 

the last example, suppose the shell to have a radius of | inch on 
the corner; 5.29 — 0.125 = 5.165 inches, the required diameter 
of the blanks. 

When a shell has a cross-section similar to the ones shown in 
Fig. 13, the required blank diameter may be calculated by the fol- 
lowing formula: 



where 



' W t 



d = Diameter of blank in inches; 

W = Weight of shell; 

^ = Weight of one cubic inch of the metal; 

t = Thickness of shell. 



DIAMETERS OF SHELL BLANKS 269 

Diameter of Blanks for Shells, j x j Inch to 6 x 6 Inches 



=: a 


Right of Shell 


i" 


i" 


S." 


i" 


li" 


A" 


il" 


2" 


2\" 


2\" 


21" 


3" 


,. 


0.56 


0.75 


0.90 


E 

1.03 


1.14 


1.25 


1.35 


1.44 


I.S2 


1.60 


1.68 


1-75 


¥' 


0.87 


1. 12 


1-32 


1.50 


1.66 


1.80 


1.94 


2.06 


2.18 


2.2Q 


2.40 


2.50 


¥ 


1. 14 


1.44 


1.68 


1.89 


2.08 


2.25 


2.41 


2.5b 


2.70 


2.84 


2.97 


3.09 


1" 


1.41 


1-73 


2.00 


2.24 


2.45 


2.65 


2.83 


3.00 


3.I6 


3-32 


3.40 


3.61 


li" 


i.b8 


2.01 


2.30 


2.56 


2.79 


3.01 


3-21 


3.40 


3.58 


3.75 


3-91 


4.07 


I-" 


1.94 


2.29 


2.60 


2.87 


3-12 


3.3b 


3-57 


3.78 


3-97 


4.15 


4.33 


4.50 


II" 


2.19 


2.50 


2.88 


3-17 


3-44 


3-08 


3.91 


4-13 


4.34 


4-53 


4.72 


4.91 


2' 


2-45 


2.83 


3-16 


3.46 


3-74 


4.00 


4.24 


4-47 


4.69 


4.90 


5.IO 


5-29 


2-" 


2.70 


3.09 


3-44 


3-75 


4.04 


4.31 


4-56 


4.80 


5.03 


5.25 


5.46 


5.66 


2-" 
2-" 


2.96 


3-30 


3-71 


4-03 


4-33 


4.61 


4.«7 


5-12 


5.36 


5.50 


5.81 


6.02 


3.21 


3.01 


3.Q8 


4-31 


4.62 


4.91 


5.18 


5.44 


5.68 


5-92 


6.1S 


6.37 


3" 


3-4(> 


3.87 


4.24 


4..S8 


4.90 


5.20 


5.48 


5.74 


6.00 


6.25 


6.48 


6.71 


3-" 


3-71 


413 


4-51 


4-«5 


5.1H 


5.4H 


5.77 


6.04 


6.31 


6.56 


6.80 


7.04 


3- 


3-97 


4-39 


4-77 


5-12 


5-45 


5-77 


6.06 


6.34 


6.61 


6.87 


7.12 


7.36 


3-" 


4.22 


4.b4 


5 -03 


5-39 


5-73 


6.05 


6.35 


6.64 


6.91 


7.18 


7.44 


7.69 


4 „ 


4-47 


4.90 


5-29 


5.66 


6.00 


6.32 


6.63 


6.93 


7.21 


7.4« 


7.75 


8.00 


4i" 


4.72 


5-15 


5-55 


S-92 


b.27 


b.6o 


6.91 


7.22 


7.50 


7.78 


8.05 


8.31 


4^ 


4-9« 


5-41 


5.81 


6.19 


0.54 


6.87 


7-10 


7.50 


7-79 


8.08 


8.35 


8.62 


4r 


5.22 


5-00 


6.07 


6-45 


6.80 


7.15 


7-47 


7.78 


8.08 


8.37 


8.65 


8.92 


5' 


S.4« 


5-92 


6-32 


6.71 


7.07 


7.42 


7.75 


8.06 


8.37 


8.66 


8.94 


9.22 


5* 


S.73 


6.17 


6.58 


6.97 


7-33 


7.68 


8.02 


8.34 


8.65 


8.95 


9.24 


9-52 


5"! 


5.Q« 


b.42 


6.84 


7-23 


7.60 


7.95 


8.29 


8.62 


8.93 


9.23 


9-53 


9.81 


if 


6.23 


6.68 


7.09 


7.49 


7.86 


8.22 


8.56 


8.89 


9.21 


9-52 


9.81 


10.10 


6" 


t).4H 


6.93 


7-35 


7-75 


8.12 


«.49 


8.83 


9.17 


9-49 


9.80 


10.10 


10.39 













Hight of SheU 












3i" 


31" 


3l" 


4" 


41" 


4¥' 


4f" 


5" 


Si" 


5l" 


51" 


6" 


1" 


1.82 


1.89 


1.95 


2.01 


2.08 


2.14 


2.19 


2.25 


2.30 


2.36 


2.41 


2.46 


5" 


2.60 


2.69 


2.78 


2.87 


2.96 


3.04 


3.12 


3.21 


3.29 


3.3b 


3.44 


3, SO 


f" 


3.21 


3.33 


3.44 


3.54 


3.b5 


3.75 


3.85 


3.95 


4.04 


4.13 


4.22 


4.31 


l' 


3-74 


3.87 


4.00 


4.12 


4.24 


4.30 


4.47 


4.58 


4.69 


4.80 


4.90 


5.00 


1?" 


4.22 


4.37 


4-51 


4.64 


4.77 


4.91 


5.03 


5.15 


5.27 


5.39 


5.50 


5.02 


I-" 


4.66 


4.82 


4.98 


5.12 


5-27 


5.41 


5-55 


5.08 


5.81 


5.94 


6.06 


6.18 


I-" 


5.08 


5.26 


5.41 


5.58 


5.73 


5.88 


6.03 


6.17 


6.31 


6.45 


6.58 


6.71 


2" 


5.48 


5.66 


5.83 


6.00 


6.16 


6.32 


6.48 


6.63 


6.78 


6.93 


7.07 


7.21 


2r 


5.86 


6.05 


6.23 


6.41 


6.58 


6.75 


6.91 


7.07 


7.23 


7.39 


7.54 


7.69 


2 k" 


6.22 


6.42 


6.61 


6.80 


6.98 


7.16 


7.33 


7.50 


7.66 


7.82 


7.98 


8.14 


2i" 


6.58 


6.79 


6.99 


7.18 


7-37 


7.55 


7.73 


7.91 


8.08 


8.25 


8.41 


8.58 


3" 


6.93 


7.14 


7-35 


7-55 


7-75 


7.94 


8.12 


8.31 


8.49 


8.66 


8.83 


9.00 


3i" 


7.27 


7.49 


7.70 


7.91 


8. II 


8.31 


8.50 


8.69 


8.88 


9.06 


9.24 


9.41 


4 


7.60 


7.83 


8.0s 


8.26 


8.47 


8.67 


8.87 


9.07 


9.26 


9.45 


9.63 


9.81 


3i" 


7.92 


8.16 


8.38 


8.61 


8.82 


9.03 


9.24 


9-44 


9.63 


9.83 


10.02 


10.20 


4" 


8.25 


8.49 


8.72 


8.94 


9.17 


9.38 


9-59 


9.80 


10.00 


10.20 


10.39 


10. s8 


4i" 


8.56 


8.81 


9.04 


9.28 


9.50 


9.72 


9.94 


10.15 


10.36 


10.56 


10.76 


10.96 


44" 


8.87 


9.12 


9.37 


9.60 


9.84 


10.06 


10.28 


10.50 


10.71 


10.92 


II. 12 


11.32 


4f 


9.18 


9.44 


9.69 


9-93 


10.16 


10.40 


10.62 


10.84 


11.06 


11.27 


11.48 


11.69 


5" 


9.49 


9.75 


10.00 


10.25 


10.49 


10.72 


10.95 


II. 18 


11.40 


11.62 


11.83 


12.04 


5 k" 


9-79 


lo.os 


10.31 


10.56 


10.81 


11.05 


11.28 


II. 51 


11.74 


11.96 


12.18 


12.39 


^K 


10.08 


10.36 


10.62 


10.87 


II. 12 


11.37 


II. 61 


11.84 


12.07 


12.30 


12.52 


12.74 


5i" 


10.38 


10.66 


10.92 


ri.i8 


11.44 


11.69 


11-93 


12.17 


12.40 


12.63 


12.85 


13.08 


b" 


10.68 


10.9s 


11.23 


11.49 


11.75 


12.00 


12.25 


12.49 


12.73 


12.96 


13.19 


13.42 



270 



PUNCH PRESS TOOLS 



PUNCH AND DIE ALLOWANCE FOR ACCURATE 
WORK 

In the blanking, perforating and forming of flat stock in the power 
press for parts of adding machines, tj-pewriters, etc., it is generally- 
desired to make two different kinds of cuts with the dies used. First, 
to leave the outside of the blank of a semi-smooth finish, with sharp 
corners, free from burrs, and with the least amount of rounding on 
the cutting side. Second, to leave the holes and slots that are per- 




Punch 




Fig. 14. — Blanking Tools 




Punch 




Fig. 15. — Perforating Tools 



forated in the parts as smooth and straight as possible, and true to 
size. The table given is the result of considerable experimenting 
on this class of work, and has stood the test of years of use since it 
'was compiled. 

The die always governs the size of the work passing thi^ough it. 
The punch governs the size of the w^ork that it passes through. In 
blanking work the die is made to the size of the work wanted and 
the punch smaller. In perforating work the punch is made to the 
size of the work wanted and the die larger than the punch. The 
clearance between the die and punch governs the results obtained. 



CLEARANCE FOR PUNCHES AND DIES 



271 



Figs. 14 and 15 show the application of the table in determining 
the clearance for blanking or perforating hard rolled steel .060 inch 
thick. The clearance given in the table for this thickness of metal 
is .0042, and Fig. 14 shows that for blanking to exactly i inch diam- 
eter this amount is deducted from the diameter of the punch, while 
for perforating the same amount is added, as in Fig. 15, to the diameter 
of the die. For a sliding fit make punch and die .00025 to .0005 inch 
larger; and for a driving fit make punch and die .0005 to .0015 inch 
smaller. 

Table of Allowances for Punch and Die for Different 
Thickness and Materials 



Thickness of Stock 
Inch 


Clearance for Brass 


Clearance for Medi- 


Clearance for Hard 


and Soft Steel 


um Rolled Steel 


Rolled Steel 


Inch 


Inch 


Inch 


.010 


.0005 


.0006 


.0007 


.020 


.001 


.0012 


.0014 


.030 


.0015 


.0018 


.0021 


.040 


.002 


.0024 


.0028 


.050 


.0025 


.003 


•0035 


.060 


.003 


.0036 


.0042 


.070 


•0035 


.0042 


.0049 


.080 


.004 


.0048 


.0056 


.090 


.0045 


.0054 


.0063 


.100 


.005 


.006 


.007 


.110 


•0055 


.0066 


.0077 


.120 


.006 


.0072 


.0084 


.130 


.0065 


.0078 


.0091 


.140 


.007 


.0084 


.0098 


.150 


.0075 


.009 


.0105 


.160 


.008 


.0096 


.0112 


.170 


.0085 


.0102 


.0119 


.180 


.009 


.0108 


.0126 


.190 


.0095 


.0114 


•0133 


.200 


.010 


.012 


.014 



CLEARANCE FOR PUNCHES AND DIES FOR 
BOILER WORK 



The practice of the Baldwin Locomotive Works on sizes up to ij 
inches is to make the punch -^^ inch below nominal size and the die 
eV inch above size, which gives gV inch clearance. Above ij inches 
the punches are made to nominal size and the dies 3V inch large, which 
allows the same clearance as before. The taper on dies below ij 
inches is i inch in 1 2 ; on sizes above i- 
inch in 12 inches. 



272 PUNCH PRESS TOOLS 



LUBRICANT FOR PRESS TOOLS 

Although there are some shops in which no lubricant is used 
when working sheet metal, and where good results are obtained, still 
it is best to use a lubricant on all classes of sheet-metal work. 

For all cutting dies on brass and steel a heavy animal oil is best. 
Pure lard oil is very satisfactory, although expensive. 

When punching copper, or German silver, a thin coating of lard 
oil or sperm oil should be spread over the sheets or strips before 
punching. A good way to do this evenly is to coat one sheet thickly 
and then feed it through a pair of rolls, after which a number of other 
sheets may be run through the rolls and thus coated evenly. For 
drawn work this method of coating the sheets from which the shells 
are to be drawn will be found to be the best, as the coating of oil on 
the stock will be very thin and it will not be found necessary to clean 
the shells afterward, the oil having disappeared during the blanking 
and drawing process. When oil is applied with a pad or brush the 
coating will be so thick that it will be necessary to clean the article 
produced. 

Drawing Steel Shells 

In drawing steel shells a mixture of equal parts of oil and black 
lead is very useful, and while it may be used warm it does not affect 
the work as much as the speed of the drawing press does; the thicker 
the stock the slower must be the speed of the punch. A heavy 
grease with a small proportion of white lead mixed in with it is also 
recommended for this purpose. 

If the drawing die is very smooth and hard at the corner of the 
"draw," or edge of the die, the liability of clogging will be reduced 
to a minimum. Often it will help to give to the die a lateral polish 
by taking a strip of emer}^ cloth and changing the grain of the polish 
from circular to the same direction as the drawing. 



Lubricants for Brass 

For drawing brass or copper a clean soap water is considered most 
satisfactory. One of the largest brass firms in this country uses a 
preparation made by putting 15 pounds of Fuller's soap in a barrel 
of hot water, and boiling until all the lumps are dissolved. This 
is used as hot as possible. If the work is allowed to lie in the 
water until a slime has formed on the shell it will draw all the 
better. A soap that is strong in resin or potash will not give 
good results. 

In drawing zinc the water should be hot, or the percentage of broken 
shells wiU be large. 

Aluminum is an easy metal to draw, but it hardens up very 
quickly. For lubricants lard oil, melted Russian tallow and vasel- 
ine are all good. The lubricant should be applied to both sides 
of the metal. 



BROACHES AND BROACHING 

Broaching is being used more and more to finish holes and even 
for slots and the outside of pieces of work. In most cases it is used 
to change a round hole to a square or other shape, such as the four 
or ten key ways used in automobile transmission. 

The chip cut by each tooth varies from o.ooi to 0.007 inch, accord- 
ing to the material being cut and the accuracy required. The teeth 
are usually undercut from 6 to 10 degrees to give a curl to the chip, 
while the top clearance is about 30 degrees. Some EngUsh practice 




The First Chip 



The Last Chip 
Fig. I 



Section of Broached Hole 



undercuts 25 degrees, having top nearly flat. The distance between 
teeth varies according to the length of the hole being broached, the 
spacing being larger for long holes so as not to have too many teeth 
engaged at once, three being a good number. Spacing varies with 
length of hole. 

In broaching square holes from the round, or in other cases where 
there is a decided change of shape, the first teeth take the widest 
cut as at vl. Fig. i. This evens up the work of the different teeth 




Fig. 2 



as to the length of surface cut as the hole approaches a square as 
seen at B. 

The blank for the cutting part of each broach is first turned taper 
by an^mount equal to the total cut of the teeth. The tooth spaces 
are then turned | inch apart and about ^2 i^^ch deep, this depending 
on the diameter of the broach, as it must not be unduly weakened; 
it is then milled ^| inch square as shown. The longer the hole the 
more chip room must be provided. 

273 



274 



BROACHES AND BROACHING 



Where the hole or other surface to be broached is short, the teeth 
are often cut on an angle to give a shearing cut. This is also done 
to prevent chatter at times, another remedy being to space the teeth 
unevenly as with reamers. 

The solid broach is used more than any other. But as tool steel 
is apt to spring in hardening, and to break out teeth at times, some 
use built-up or sectional broaches, espe- 
cially on large work where the solid 
broach costs heaxaly. Some use low 
carbon steel, case hardened. These 
sectional broaches are made in a variety 
of ways. Figs. 2 to 4 showing a few 
examples. In Fig. 2 sections are set in 
on the side, while in Figs. 3 and 4 the 
sections are practically disks held on a 
central arbor. In some cases seyeral 
teeth are made on one section. Fig. 4 is made in the same way for 
broaching internal gears having 66 teeth, 20 diametral pitch and ^ 
inch face. Each tooth cuts 0.006, the last three teeth being straight 
to insure the size being accurate. 




Fig. 




Fig. 4 
BROACHING ROUND HOLES 

Round holes have been broached instead of reamed in some places 
for many years and the practice is growing. It was formerly con- 
fined to soft metal, such as shaft bearings, but is now being made 
to cover all the metals, in some few cases broaching from a cored 
hole. For small work a small arbor press \\ith a sort of sub-press 
can be used to advantage. For larger work the arbor press operated 
by power is very good and of course the regular broaching machine 
can be used in any case. 

Two broaches used in one shop are shown in Fig. 5, other sizes 
can be made in proportion. These were used in a hand arbor press. 
The first 5 or 6 teeth do most of the cutting as these broaches only 
finish the holes instead of reaming. In some cases with broaches for 
soft metal bearings and even in cast iron, the large end is left plain 
and a trifling amount larger than the last tooth. It then acts as a 
burnisher and compresses the metal. This requires a large amount 
of power. • 

In broaching round holes in cast iron, the broach was made from 
0.0002 to 0.0003 i^ch larger than the nominal size and the land was 
0.012 as shown. The holes were drilled close to size so as to leave 
very little work for the broach. In this case about 0.002 inch was 
left for broaching. 



BROACHING SQUARE HOLES 



275 



The comparison between broaching and reaming in this case is 
interesting. The reamers would wear appreciably below size in 25 
holes while one broach finished 5000 holes to size. 



i. 



-3V,6 



S^Vie- 



m. 



14 Broach 



-0-012 



I liiii 







-2-%- 


'1^ 


" 


% 


'T 


[| 


iii 


i 





IH" Broach 



B SS; 




TO SAVE TIME IN BROACHING OUT SQUARE HOLES 

The fit of the gears on a square shaft depends almost entirely 
on the flat surfaces at or near the corners. With this in mind, it is an 
econom}' to bore or drill the round hole in the gear slightly larger than 
the diameter across the flats of the squared shaft, as shown in Fig. 6. 

Taking a ij-inch 
square shaft and bor- 
ing the hole x\ inch 
larger or ly^ inches in 
diameter, we see in 
the illustration exact- 
ly what this would 
mean. The amount 
of metal to be cut out 
would be materially 
reduced, the portion 
A to B not being 
touched by the broach 
in any way. Yet the 
remaining surface in 

the corners would be ample to carry all the load of the gears at work, 
and the clearance A to B would allow the best of lubrication. 

The center relief, as shown, gives considerable added chip space as 
well as reduces the amount of chip, thus allowing a heavier chip per 
tooth. This may either reduce the length of the broach or allow a 
longer hole (such as two gears at once) to be broached with the same 
length of broach. 

The set of 7 broaches shown in Fig. 7 show the practice of the 
Brown & Sharpe Mfg. Co. in making automobile transmission gears. 
The gears are of a tough alloy steel making the 7 necessary to secure 
an accurate hole of ij inches across the flats. Each broach is 30I 
inches long, the cutting portion being only 17^ inches. The method 
of holding the shank can be readily seen. 



''''///////^^///////MV////^A 

Fig. 6 



276 



BROACHES AND BROACHING 




S 1.5745 
§ 1.5745 
-%5745 



is |§ 



1.357 1.313 1.280 1.258 

1.3595 1.315 1.2815 1.259 
1.362 1.317 1.283 1.260 
1.3645 1.319 1.2845 1.261 
1.367 1.321 1.286 1.262 
1.3695 1.323 1.2875 1.263 
1.372 1.325 1.289 1.264 
1.3745 1,327 1.2905 1.265 
1.377 1.329 1.292 1.266 
1.3795 1.331 1.2935 1.267 
1.382 1.333 1.295 1.268 
1.3845 1.335 1.2965 1.269 
■=J 1.387 1.337 1.298 1.270 
1.3895 1.339 1.2995 1.271 
1.392 1.341 1.301 1.272 
1.3945 1.343 1.3025 1.273 
1.397 1.345 1.304 1.274 
1.3995 1.347 1.3055 1.275 
1.402 1.349 1.307 1.276 
1.4045 1.351 1.3085 1.277 
I 1.407 1.353 1.310 1.278 
1.4095 1.355 1.3115 1.279 
1.412 1.357 1.313 .1.280 



^718^ 



& 

^w^ Fig. 7 



SIX-SPLINE FITTINGS 



277 



6 Spline Fittings 



Permanent Fit 




To blide vben not 
Under Load 

I 




To BUde when Under 
Load 




6-Spline Fittings for Automobiles 



From sixth Report of Broaches Division S.A.E. Accepted at 
Meeting of Society, January, 1914 



C . 


D 


d 


w 


T 


D 


d 


w 


T 


D 


d 


w 


T 


za 




























• 750 


.„ 


.188 


80 


•750 


.638 


.188 




•750 


.600 


.188 






•749 


.674 


.187 


•749 


.637 


.187 




.749 


.599 


.187 


152 




.875 


.788 


.219 


109 


.875 


•744 


.219 




•875 


.700 


.219 






.874 


.787 


.218 


•874 


•743 


.218 


159 


•874 


•699 


.218 


207 




1. 000 
■999 


.900 
.899 


.250 
.249 


143 


1. 000 
•999 


•850 
.849 


.250 
.249 


208 


1. 000 
•999 


.800 
•799 


-250 
•249 


270 




1. 125 


I.013 


.281 


■80 


I-I2S 


•956 


.281 


263 


I^I25 


.900 


.281 




1.124. 


1.012 


.280 


1.124 


1-955 


.280 


i.i^ 


•899 


.280 


342 




1.250 
1.249 


I-125 
1. 124 


-313 
-312 


.« 


1.250 
1.249 


1:063 
1.062 


•313 
•312 


325 


1.250 
1.249 


1. 000 
•999 


•313 
•312 


421 




1-375 
1-374 


1.238 
1-237 


•344 
-343 


269 


1-375 
1-374 


1. 169 
1. 168 


•344 
•343 


393 


I-37S 
1-374 


1. 100 
1.099 


•344 
-343 


510 




1.500 


I-3SO 


•375 


321 


1-500 


1-275 


•375 


468 


1.500 


1.200 


-375 


608 




1-499 


1-349 


-374 


1.499 


1.274 


•374 


1.499 


1. 199 


-374 




1.625 


1.463 


.40b 


376 


1.625 


I-381 


.406 


1 


1.625 


1.300 


.406 






1.624 


1.462 


■405 


1.624 


1.380 


•405 


550, 


1.624 


• 1.299 


-405 


713 




I-750 


I-57S 


.438 


436 


1-750 


1.488 


-438 


637 


1-750 


1.400 


-438 


827 




1.749 


1-574 


•437 


1.749 


1.487 


-437 


1.749 


1-399 


-437 




2.000 


1.800 


.500 


S70 


2.000 


1.700 


.500 


833; 


2.000 


1.600 


.500 


1080 




1.998 


1.798 


-498 


1.998 


1.698 


-498 


1.098 


1.598 


•498 


2\ 


2.250 


2.025 


-S63 


721 


2.250 


I^9i3 


-56^ 




2.250 


1.800 


-56s 


1367 


2.248 


2.023 


-561 


2.248 


1.912 


-561 




2.248 


1-708 


.S6i 


2? 


2.500 


2.250 


-625 


891 


2.500 


2.125 


.625 




2.500 


2.000 


.625 


1688 


2.49« 


2.248 


-623 


2.498 


2.123 


-623 




2.498 


1.998 


-623 


3 


3.000 


2.700 


-750 


1283: 


3.000 


2-550 


• 750 


1873 


3.000 


2.400 


-750 




2.99« 


2.698 


-74« 


2.998 


2-548 


.748 


2.998 


2.398 


-748 


2430 



T = 1000 X 6 (No. of Splines) X Mean Radius X /s X i = inch-pounds torque 
capacity per inch bearing length at 1000 lbs. pressure per square inch on sides of 
splines. No allowance is made for radii on comers nor for clearances. 



278 



BROACHES AND BROACHING 



10 Spline J'ittings 




To Slide when not 
Under Load 




To Blide vhen Under 




io-Spline Fittings for Automobiles 



From Sixth Report of Broaches Division S.x^.E. Accepted at 
Meeting of Society, January, 19 14 



1 . 

6 § 


D 


d 


w 


T 


D 


'd 


• w 


T 


D 


d' 


w 


T 


!z;q 


























3 


•750 


.683 


.117 


120 


•750 


-645 


•117 


.83 


.750 


.608 


.117 


241 




•749 


.682 


.116 


•749 


.644 


.116 


•749 


.607 


.116 




.«75 


-796 


.137 


165 


•875 


•753 


• 137 


248 


•875 


•709 


-137 


329 




.874 


•795 


.136 


•874 


•752 


• 136 


•874 


.708 


.136 




1. 000 


.910 


.1S6 


,.' 


1. 000 


.860 


.156 


326 


1. 000 


.810 


.156 






•999 


.909 


-155 




•999 


•859 


• 155 


•999 


.80Q 


•155 


430 


t1 


1. 125 


1.024 


.176 


271 


1. 125 


.968 


.176 


4I2| 


I^I25 


.911 


.176 


545 




1. 124 


1.023 


•175 


1. 124 


■967 


•175 


1. 124 


.910 


•175 


tI 


I.2SO 


1-138 


•195 


336 


1-250 


1^075 


•195 


508 


1.250 


1.013 


• 195 


672 




1.249 


I-137 


.194 


1.249 


1.074 
1. 183 


.194 


1.249 


1.012 


.194 


jI 


1-375 


1. 251 


•215 


406, 


1-375 


• 215 


6m' 


i^375 


1. 114 


• 215 


813 




1-374 


1.250 


.214 


1-374 


1. 182 


.214 


i^374 


1. 113 


.214 


li 


1.500 


1-365 


•234 


483 


1.500 


1.290 


•234 


732 


1.500 


1-215 


• 234 


967 


1.499 


1-364 


•233 


1.499 


1.289 


•233 


1.499 


1. 214 


•233 


I 5 


I-t.2S 


1.479 


•254 


566 


1.62s 


1.398 


■ 254 


860 


1.625 


1.316 


• 254 


"35 




1.624 


1.478 


•253 


1.624 


i^397 


•253 


1.624 


I-315 


• 253 


I? 


1-750 


1-593 


•273 


658 


I-750 


1-505 


• 273 


997 


I-750 


1.418 


• 273 


1316 




1.749 


1-592 


.272 


1.749 


1-504 


.272 


1.749 


1.417 


.272 




2.000 


1.820 
1.818 


.ST2 


860 


2.000 


1.720 


.^12 




2.000 


1.620 


.M2 






1.998 


.310 


1.998 


1.718 


.310 




1.998 


1.618 


.310 




2\ 


2.250 


2.048 


•351 


1088 


2.250 


i^935 


•351 


1647 


2.250 


1-823 


•351 


2176 


2.248 


2.046 


•349 


2.248 


i^933 


•349 


2.248 


1.821 


•349 


2i 


2.500 


2.275 


•390 


1343 


2.500 


2.150 


•390 


2034 


2.500 


2.025 


•390 


2688 


2.498 


2.273 


•388 


2.498 


2.148 


.388 


2.498 


2.023 


•388 




3.000 


2.730 


.468 




3.000 


2.580 


.468 




3.000 


2.430 


.468 


3869 




2.998 


2.728 


.466 




2.998 


2-578 


.466 


1 


2.998 


2.428 


.466 



T = 1000 X 10 (No. of Splines) X Mean Radius X h X 1 = inch-pounds torque 
capacity per inch bearing length at 1000 lbs. pressure per square inch on sides of 
.Splines. No allowance is made for radii on corners nor for clearances. 



BOLTS, NUTS AND SCREWS 

U. S. STANDARD BOLTS AND NUTS 

The U. S. Standard for bolts, nuts, etc., called also Sellers' Stand- 
ard, Franklin Institute Standard, and American Standard, was recom- 
mended in 1864 by the Franklin Institute for general adoption by 
engineers. (See Note). 



Strength of U. 


S. Standard 


Bolts 


FROM 


I TO 


3^^ Diameter 


Bolt 


Areas 


Tensile Strength 




Shearing 


Strength 


^ 


! 




-S 

n 


I 


H. 


a 


Full Bolt 


Bottom of Thread 


t^ 






^ 

*« 


i 


a 


r, 








-^ 


^a 


M 


i^ 


i^ 


1 


L 


1 



s 


^ 




h 


y 


u 


l^ 


U 


.2 


h5" 


S 

3 





fi 


:^ 


:^ 


fs. 


!^ 


TH. 


a 





Z 


fa 


03 


< 


< 


< 


< 


<: 


< 


< 


I 


20 


.049 


.027 


270 


340 


470 


380 


490 


200 


270 


"16 


18 


.077 


•045 


450 


570 


790 


580 


770 


340 


450 


f 


16 


.110 


.068 


.680 


850 


1,190 


830 


1,100 


510 


680 


t\ 


14 


.150 


•093 


930 


1,170 


1,630 


1,130 


1,500 


700 


930 


i 


13 


.196 


.126 


1,260 


1,570 


2,200 


1,470 


1,960 


940 


1,260 


1% 


12 


.248 


.162 


1,620 


2,030 


2,840 


1,860 


2,480 


1,220 


1,620 


f 


II 


•307 


.202 


2,020 


2,520 


3,530 


2,300 


3,070 


1,510 


2,020 


1 


10 


.442 


.302 


3,020 


3,770 


5 ,290 


3,310 


4,420 


2,270 


3,020 


1 


9 


.601 


.419 


4,190 


5,240 


7,340 


4,510 


6,010 


3,150 


4,190 


I 


8 


.785 


•551 


5,510 


6,890 


9,640 


5,890 


7,850 


4,T3o 


5,510 


ll 


7 


•994 


.693 


6,930 


8,660 


12,130 


7,450 


9,940 


5,200 


6,930 


li 


7 


1.227 


.890 


8,890 


11,120 


15,570 


9,200 


12,270 


6,670 


8,900 


'f 


6 


1.485 


1.054 


10,540 


13,180 


18,450 


11,140 


14,850 


7,910 


10,540 


li 


6 


1.767 


1.294 


12,940 


16,170 


22,640 


13,250 


17,670 


9,700 


12,940 


if 


5i 


2.074 


1-515 


15,150 


18,940 


26,510 


15,550 


20,740 


11,360 


15,150 


if 


5 


2.405 


1.745 


17,450 


21,800 


30,520 


18,040 


24,050 


13,080 


17,440 


ll 


5 


2.761 


2.040 


20,490 


2=;, 610 


^v5,86o 


20,710 


27,610 


15,370 


20,490 


2 


4i 


.142 


2.300 


23,000 


28,750 


40,250 


23,560 


31,420 


17,250 


23,000 


2? 


4i 


3-976 


3.021 


30,210 


37,770 


^2,870 


29,820 


39,760 


22,660 


30,210 


2j 


4 


4.909 


3.716 


37,160 


46,450 


65 ,040 


36,820 


49,090 


27,870 


37,160 


2f 


4 


5 -940 


4.620 


46,200 


57,750 


80,840 


44,580 


59,400 


34,650 


46,200 


3 


3i 


7.069 5.428 


54,280 


67,8:;o 


94.990 


53.020 


70,69c 


40,710 


54,280 



Note. — The distance between parallel sides of the bolt head and nut for a rough 
bolt is one and one-half diameters of the bolt plus one-eighth of an inch. The thickness 
of the head in this system for a rough bolt is equal to one-half the distance between its 
parallel sides. The thickness of the nut is equal to the diameter of the bolt. It 
was originally recommended in this system that the thickness of the head for a 
finished bolt be equal to the thickness of the nut, and that the distance between the 
parallel sides of a bolt head and nut and the thickness of the nut be one-sixteenth 
mch less for finished parts than for rough. However, it is the practice of bolt and 
nut manufacturers to make finished U. S. nuts to the same dimensions as established 
for rough ones, and where finished heads are required to the U. S. Standard they are 
customarily made to the same dimensions as rough heads unless otherwise specified. 

279 



28o 



BOLTS, NUTS AND SCREWS 



5>Q 



Roug-h 



Heads and Kuts 
.A X 1.155. C=A X 1.414 





U. S. Standard Bolts and Nuts 

ROUGH 



Dia. of 


Threads 
per Inch 


Across 
Flats 


Across Corners 


Thickness 


Depth of 


Bolt 


B 


C 


Head 


Nut 


Thread 


1 

4 


20 


h 


H 


If 


1 


i 


•0325 


A 


i8 


M 


ii 


H 


• H 


tV 


.0361 


f 


i6 


H 


li 


fi 


H 


1 


.0406 


t\ 


14 


If 


ft 


i/i 


If 


tV 


.0464 


h 


13 


1 


i.\ 


li ■ 


i\ 


i 


.0500 


T% 


12 


U 


li 


If ' 


H 


t\ 


.0542 


1 


ir 


iiV 


iM 


li 


H 


1 


.0590 


f 


10 


li 


Iff 


Iff 


f 


f 


.0650 


i 


Q 


iTff 


41 


23\ 


11 


I 


.0722 


I 


8 


If 


li 


2if 


if 




.0812 


li 


7 


III 


2^\ 


2t\ 


If 


Ij 


.0928 


1? 


7 


2 


2A 


2M 


I 


li 


.0928 


l| 


6 


2tV 


2H 


3iV 


I3V 


If 


.1083 


li 


6 


2i 


2f 


3li 


iiV 


li 


.1083 


If 


5 


2f 


3fV 


3ll 


li 


^4i 


.1300 


2 


4i 


3i 


3tl 


4|| 


ii\ 


2 


.1444 


2i 


4j 


3i 


4o% 


4M 


If 


2i 


.1444 


2i 


4 


3i 


4li 


sH 


III 


2i 


.1625 


2| 


4 


4i 


4tl 


^eh 


2| 


2f 


.1625 


3 


3i 


4l 


5M 


6H 


2r% 


3 


•1857 



Note. — U. S. Government Standard Bolts and Nuts are made to 
above U. S. or Sellers' Standard Rough Dimensions. The sizes of 
finished bolt heads and nuts are the same as the sizes of the rough 
ones, that is for finished work the forgings must be larger than for 
rough, thus the same wrench may be used on both black and finished 
heads and nuts. 



XJ. S. STANDARD BOLTS AND NUTS 



281 



Finished 



JHeads and Nuts 







w\ 



m 



See Note 

U. S. Standard Bolts and Nuts. — finished heads and nuts 

FINISHED heads AND NUTS 



See Note 


i 


"o 

V 
N 


1 

Q 
a 
h 


3 

"0 

."2 


-a 


Safe Strain in lbs. 
Iron at 50,000 
lbs. per Sq. In. 
Factor of Safety 


5 


i5 

< 


g 

c 

U 

i 

1 


i 


tV 


i 


t\ 


.185 


.191 


.0063 


.0260 


260 


i\ 


H 


If 


i 


.2408 


.246 


.0069 


.0452 


452 


1 


f 


II 


tV 


.2938 


if 


.0078 


.0677 


677 


7 


II 


If 


i 


•3447 


If 


.0089 


.0932 


932 


h 


if 


if 


tV 


.4001 


il 


.0096 


•1257 


1257 


9 


If 


leV 


§ 


•4542 


M 


.0104 


.1620 


1620 


•f 


I 


l3\ 


T% 


.5069 


If 


.0114 


.2018 


. 2018 


f 


lA 


i|i 


U 


.6201 


f 


.0124 


.3020 


3020 


1 


If 


iM 


If 


•7307 


tl 


.0139 


.4194 


4194 


T 


lT6 


ill 


H 


.8376 


II 


.0156 


•5509 


5509 


li 


If 


.2^1 


itV 


•9394 


U 


.0179 


.6930 


6930 


li 


iH 


2M 


It\ 


1.0644 


1/5 


.0179 


.8890 


8890 


If 


2| 


2ll 


lA 


^•i585 


iH 


.0208 


1.054 


10540 


li 


2^ 


41 


ixV 


1-2835 


iM 


.0208 


1-293 


12930 


If 


2H 


3a\ 


IH 


1 .4902 


Iff 


.0250 


1.744 


17440 


2 


3j\ 


3H 


lil 


1.7113 


III 


.0278 


2^3 


23000 


2i 


3tV 


3fi 


2-h 


1-9613 


iH 


.0278 


3.021 


30210 


2i 


3il 


4M 


2tV 


2.1752 


2tV 


•0313 


3-714 


37140 


2f 


4t\ 


4tl 


2^ 


2.4252 


2tV 


•0313 


4.618 


46180 


3 ■ 


4A 


53\ 


2i| 


2.6288 


2tf 


•0357 


5-427 


54270 



282 



BOLTS, NUTS AND SCREWS 





[I 






d 


^ 


V 






lllllr 


\ 




/ 


_JI 


1 


I 


N 






) 




u 




^ 










Machine Bolts with Manufacturers Std 


Heads 




1 


Hex', and Square Heads 
(National Machinery Co.) 


Hex. and Square Nuts 




















a 






-a 












i 






J 


.c^ 


V 


et^ 


^ 


I 


2i 

f5 


E2J 


5| 






S 3 

O^ 


Bz 

ua 


K C 


"o 


o 


S3 


^?« 


s d 








.i 


6 


13 oo 


^ffi 




2k 


iffi 


o cr 


•,H^ 


Q 


^ 


< 


< 


H 


< 


<: 


< 


H 


1 




3 


7 


3 


"? 


1 


5 


3 


4 




« 


tV 


16 


To 


2 


8 


16 


A 


i8 


it 


H 


1 
4 


H 


ft 


1 


i 


f 


i6 


ft 


f 


A 


1 


2 3 
32 


57 

04 


-h 


T^^ 


14 


M 


ft 


u 


If 


ft 


I 


f 


h 


13 


3 
4 


il 


1 


if 


if 


1/2 


t\ 


t\ 


12 


II 


ft 


11 


II 


I^I 


I/." 


1 


5 
8 


II 


H 


I 


H 


I 


is\ 


I|| 


T% 


1 


lO 


li 


it\ 


A 


it\ 


Ifi 


iM 


W 


1 


9 


IT^^ 


If 


H 


If 


iM 


lit 


if 




8 


l| 


lA 


3 

4 


it\ 


lit 


2ii 


if 


li 


7 


lii 


If 


II 


lit 


23% 


2^ 


l| 


li 


7 


l| 


III 


if 


2 


2^ 


2ff 


t1 


If 


6 


2tV 


2i 


lA 


2A 


2M 


33% 


If 


I^ 


6 


2i 


2A 


li 


2f 


2f 


3lf 


I^ 


If 


5l 


2tV 


2| 


I/. 


2A 


2ii 


3l 


if 


If 


5 


2f 


2H 


ir\ 


2f 


3A 


3fl 


l| 


l| 


5 


2H 


2| 


iM 


2H 


3ii 


Ah 


l| 


2 


4l 


3 


3tV 


i| 


3i 


3ff 


4fl 


2 



Note. — Nuts supplied by different makers for manufacturers 
standard bolts vary somewhat as regards thickness. The above 
nut sizes are Hoopes and Townsend Standard. 



SET SCREWS 



283 




c^ — , Cone Point and " ™ , „, ^ „ • x 

^^^ Hanger Set Point 0, Flat Pivot Point 



^^_^ c5 >;* § 







IOia.=lBot. ofThd. 



/»^6fl^ 



Set Screws 





Hartford Machine Screw Co. Standard 




1 

2: 


-0 
a 






U 

2 




■-3 


1 

1 


.bib 


D 




L 


H 


Hi 


c 


M 


R 


F 


N 


I 

1 

1 
f 

i ■ 

I 


20 
18 
16 
14 
13 
12 
II 
10 
9 

•8 


1 
f 

7 
8 

I 


M 

If 

1 


i 

1 


1 

M 
.A 


t¥8 

If 
li 
If 

i 


i 

h 

1 

i 

I 


.019 
.021 
.023 
.027 
.031 
.032 
.034 
•037 
.041 
.047 


.075 
.083 

.094 
.107 
.125 

•125 
.130 
.150 
.166 
.187 



284 



BOLTS, NUTS AND SCREWS 





E^""^ 



Hartford Machine Screw Co., Standard 





Hexagon Head Cai 


Screws 




Square Head Cap Screws 






. 


. 




-d 


^ 


.. 
















ri 












Id 

da 


Is 
11 




< 

.2^ 


ll 


3 

1 


Is 

la 


< 




_3 


s 


iz; 


Q 


Q 


H 


p;; 


Q 


P 


H 


rt 


D 




A 

1 


B 


C 


R 


A 


B 


c 


R 


1 

4 


20 


T% 


1 
4 


3 
4 


il 


1 


1 


IS 




i8 


37 


1 




55 


5 


•7 


5 


15 


IT 


61 


2 


16 


64 


8 


16 


16 


16 


1 


i6 


u 


A 


t 


H 


M 


\ 


f 


itV 


tV 


14 


II 


t 


tV 


i^\ 


H 


-h 


T6 


it\ 


h 


13 


1 


3 
4 


^ 


1/2 


M 


5 
8 


\ 


It\ 


J% 


12 


it 


H 


t\ 


lit 


M 


ii 


-h 


III 


1 


II 


lA 


I 


f 


i| 


itV 


f 


1 


iH 


1 


10 


I.\ 


I 


3 

4 


Iff 


lif 


7 
8 


I 


III 


1 


9 


iM 


li 


1 


iM 


iM 


li 


7 
8 


2f 


I 


8 


ItV 


li 


I 


2A 


III 


l| 


I 


2|| 


li 


7 


iH 


If 


li 


2f 


lit 


If 


li 


3 


li 


7 


4i 


i^ 


li 


2M 


2\ 


li 


li 


3t^ 



FILLISTER HEAD CAP SCREWS 




^S^''"'T3 







:r+^ 



285 

□ 






Collar Head Screws 


Fillister Head Cap Screws 
(P. & .W. St'd) 


.3 



1 

h 


< 

ii 

15 

Q 


< 
1^ 


1 

C 






to 

y 
C 


73 

.2 


-a 
X 

i 
Q 


1 


§ 





'0 

.•2 




a 
Q 


Q 


D 




A 


B 


C 


E 


F 


R 


A 


c 


H 


c + 

H 


E 


F 

3^2 


L 


i 


40 


H 


1 


6^4 


i 


tV 


i 


il 


A 


3^ 


1 


.025 


/. 


1% 


32 


it 


A 


^2 


H 


^V 


1 


i 


1 


aV 


/l 


•039 


A 


1 


1 
4 


20 


H 


I 


9 
32 


tV 


3^^ 


i 


li 


A 


3V 


A 


.058 


a\ 


s% 


tV 


18 


tV 


t\ 


fl 


i 


i 


i* 


Te 


A 


e\ 


ft 


.071 


6\ 


A 


i 


16 


H 


1 


M 


f 


s% 


if 


i 


i 


i\ 


fl 


.086 


eV 


i 


tV 


14 


f 


tV 


M 


i* 


t\ 


if 


i\ 


i 


e\ 


fl 


.099 


6t 


i 


1 


13 


M 


i 


9 

T6 


H 


li 


IT^6 


H 


A 


e\ 


If 


.112 


i 


A 


ri: 


12 


fi 


t\ 


f 


it 


T2 


lA 


i 


1 


^4 


II 


•133 


6\ 


i 


t 


II 


It 


1 


H 


I 


i 


lA 


i 


tV 


tV 


§ 


'^33 


?^ 


I'S 


f 


10 


itV 


f 


If 


li 


A 


it\ 


ixV 


i 


tV 


A 


•133 


A 


1 


1 


9 














lA 


A 


A 


f 


•133 


3^ 


A 


I 


8 














If 


1 


tV 


if 


.165 


i 


1 



286 



BOLTS, NUTS AND SCREWS 



u m^~^ 




Flat, Round and Oval Fillister Head Cap Screws 





^ 




^^ 




"rt 


^ 








a^^ 


d"^ 


1 




t3 

•0 


^ 


1 

:3 





2 
u 

2? 




CO 


CO 4J 
J3 rt 




^1 


























,^ 


nS. 


.2 


j'^ 


"^ 


?,K 




:2 


OJ 


^0 


(ui; rt 


^iitn 


Q 


^ 


P 


ei 


h:1 


0^ 


;^ 


Q 


Q 


Q 


a 


D 




A 


c 


S 


H 


R 


E 


F 


G 


L 


M 


I 


40 


tV 


1 


sV 


o\ 


\ 


.032 


A 


^\- 


i 


3^ 


t\ 


32 


i 


iV 


3V 


^2 


5 

T6 


.040 


tV 


A 


t\ 


1% 


i 


20 


f 


i 


a\ 


s% 


1 


.064 


1^ 


■i-. 


i 


i^ 


A 


18 


tV 


A 


iV 


II 


t 


.072 


^\ 


\ 


t\ 


\ 


1 


16 


/o 


f 


tV 


il 


1 


.091 


3^2 


e\ 


f 


tS 


rV 


14 


f 


tV 


tV 


1 


1 


.102 


^'l 


U 


tV 


1 


J 


13 


f 


i 


tV 


t\ 


ItV 


.114 


i 


1% 


i 


t\ 


t\ 


12 


11 


tV 


tV 


u 


Ij 


.114 


e\ 


-i-2 


T^^ 


\ 


1 


II 


i 


1 


fs 


a 


li 


.128 


A 


-Jl 


1 


t\ 


i 


10 


I 


1 


T^5 




li 


•133 


tV 


J% 


i 


H 


i 


9 


ll 


1 


tV 


11 


If 


'-^33 


3^2 


fi- 


t 


if 


I 


8 


li 


I 


3^. 


ll 


If 


.165 


i 


1 


I 


ft 



BUTTON AND COUNTERSUNK HEAD CAP SCREWS 287 





Button Head Cap Screws 


Flat 


4.NB Oval Countersunk Head 
Cap Screws 








T3 


-d 


















^ 


T3 
ll 


-0 


1 


1 







,1 


"0 


2 
"0 


"0 




a 





'o i-i 


•0 


•£■ 


3 


XI 


S 


"o 


ti 


.3 




■^ "^ 


11 


rt 


oS. 


.2 


c 


•a 


:2 


^ 


.2 


t 


'% 


12 


^^ 


Q 


^ 


Q 


Jli 


« 


^ 


Q 


Q 


^ 


^ 


Q 


« 


D 




A 


C 


R 


E 


F 


A 


C 


R 


E 


F 


G 


i 


40 


aV 


0¥ 


6^4 


•035 


A 


i 


h 


f 


.040 


^\ 


6^ 


A 


32 


A 


A 


A 


.051 


,tV 


1 


A 


h 


.064 


lo 


tV 


1 - 
4 


20 


tV 


3V 


sV 


.072 


T^T 


if 


A 


If 


.072 


6\ 


6^5 


A 


18^ 


A 


3^^ 


3^ 


.091 


A 


f 


3V 


if 


.102 


A 


A 


1 


16 


f 


A 


A 


.102 


h 


3 
4 


il 


li 


.114 


6^ 


/^ 


tV 


14 


3 

4 


f 


1 


.114 


i 


if 


il 


I3V 


.114 


i 


i 


f 


13 


if 


M 


it 


.114 


5 

32 


I 


it 


lA 


.128 


A 


A 


T% 


12 


if 


M 


M 


.114 


fi 


I 


A 


li 


•133 


ii 


ii 


t 


II 


I 


1 


h 


•133 


A 


li 


If 


lii 


•^?>Z 


-h 


A 


f 


10 


li 


f 


1 


•133 


3V 


If 


tV 


2tV 


•133 


-h 


A 



288 



BOLTS. NUTS AND SCREWS 





k-'^Zga 



Machine Screws. American Screw Company 









Flat Head 






Round Head 


No. 


A 












B 


C 


E 


F 


B 


C 


E 


F 


2 


.0842 


.1631 


•0454 


.030 


.0151 


•1544 


.0672 


.030 


.0403 


3 


.0973 


.1894 


•0530 


.032 


.0177 


.1786 


.0746 


.032 


.0448 


4 


.1105 


.2158 


,0605 


•034 


.0202 


.2028 


.0820 


.034 


.0492 


5 


.1236 


.2421 


.0681 


.036 


.0227 


.2270 


.0894 


.036 


•0536 


6 


.1368 


.2684 


•0757 


•039 


.0252 


.2512 


.0968 


•039 


.0580 


7 


.1500 


.2947 


.0832 


.041 


.0277 


•2754 


.1042 


.041 


.0625 


8 


.1631 


.3210 


.0908 


.043 


•0303 


.2996 


.1116 


•043 


.0670 


9 


.1763 


•3474 


.0984 


•045 


.0328 


.3238 


.1190 


.045 


.0714 


lO 


.1894 


•3737 


.1059 


.048 


•0353 


•3480 


.1264 


.048 


.0758 


12 


.2158 


.4263 


.1210 


.052 


.0403 


.3922 


.1412 


.052 


.0847 


14 


.2421 


.4790 


.1362 


•057 


•0454 


.4364 


.1560 


•057 


.0936 


i6 


.2684 


•5316 


•1513 


.061 


.0504 


.4806 


.1708 


.061 


.1024 


i8 


.2947 


.5842 


.1665 


.066 


•0555 


.5248 


.1856 


.066 


.1114 


20 


.3210 


.6368 


.1816 


.070 


.0605 


.5690 


.2004 


.070 


.1202 


22 


•3474 


•6895 


.1967 


•075 


.0656 


.6106 


.2152 


•075 


.1291 


24 


•3737 


.7421 


.2118 


.079 


.0706 


.6522 


.2300 


.079 


.1380 


26 


.4000 


.7421 


.1967 


.084 


.0656 


.6938 


2448 


.084 


.1469 


28 


.4263 


.7948 


.2118 


.088 


.0706 


•7354 


.2596 


.088 


•1558 


30 


.4526 


.8474 


.2270 


•093 


•0757 


.7770 


•2744 


•093 


.1646 



Dimensions given are maximum, the necessary working varia- 
tions being below them. 



FILLISTER HEAD MACHINE SCREWS 



289 




U>^<22>i 



Machine Screws. xA.merican Screw Company 









Fillister Head 






No. 


A 

1 










G 


B 


C 


D 


E 


F 


2 


0842 


•1350 


•0549 


.0126 


.030 


.0338 


.0675 


.3 


0973 


.1561 


.0634 


.0146 


.032 


.0390 


.0780 


4 


1105 


.1772 


.0720 


.0166 


•034 


•0443 


.0886 


5 


1236 


.1984 


.0806 


.0186 


.036 


.0496 


.0992 


6 


1368 


.2195 


.0892 


.0205 


•039 


•0549 


.1097 


7 


1500 


.2406 


.0978 


.0225 


.041 


.0602 


.1203 • 


8 


1 63 1 


.2617 


.1063 


.0245 


.043 


.0654 


.1308 


9 


1763 


.2828 


.1149 


.0265 


•045 


.0707 


.1414 


10 


1894 


.3040 


•1235 


.0285 


.048 


.0760 


.1520 


12 


2158 


.3462 


.1407 


.0324 


.052 


.0866 


•1731 


14 


2421 


.3884 


.1578 


.0364 


•057 


.0971 


.1942 


16 


2684 


•4307 


•1750 


.0403 


.061 


.1077 


•2153 


18 


2947 


.4729 


.1921 


•0443 


.066 


.1182 


.2364 


20 


3210 


•5152 


.2093 


.0483 


.070 


.1288 


.2576 


22 


3474 


•5574 


.2267 


.0520 


•075 


.1384 


.2787 


24 


3737 


•5996 


.2436 


.0562 


.079 


.1499 


.2998 


26 


4000 


.6419 


.2608 


.0601 


.084 


.1605 


.3209 


28 


4263 


.6841 


.2779 


.0641 


.088 


.1710 


.3420 


30 


4526 


.7264 


.2951 


.0681 


•093 


.1816 


•3632 



290 BOLTS, NUTS AND SCREWS 

American Screw Company. Standard Threads per Inch 



No. 


2 


3 


4 


5 


6 


7 


8 


9 10 


12 


Threads 
per Inch 


48 
64 


48 
56 


32,36 
40 


30 
32 
36 


30 
32 


30 
36 


24, 30, 
32 


20 

24 


No. 


14 


16 


18 


20 


22 


24 


26 


28 


30 


Threads per 
Inch 


18 

20, 

24 


16,18, 
20 


16,18 


14 
16 
18 


14,16 



A.S.M.E. STANDARD PROPORTIONS OF MACHINE SCREWS 

The diagram and tables herewith show the proportions of machine 
screws as recommended by the committee of the American Society 
of Mechanical Engineers on Standard Proportions for Machine 
Screws, the report of this committee being adopted by the Society 
at its spring meeting, 1907. 

The included angle is 60 degrees, and the flat at top and bottom 
of thread is one eighth of the pitch for the basic or standard diam- 
eter. There is a uniform increment of 0.013 inch, between all sizes 
from 0.06 to 0.19 (numbers o to 10 in the tables which follow) and 
of 0.026 inch in the remaining sizes. This change has been made 
in the interest of simplicity and because the resulting pitch diameters 
are more nearly in accord with the pitch diameters of screws in pres- 
ent use. 

• The pitches are a function of the diameter as expressed by the 
formula >- 

Threads per inch = =- — -^ , 

^ D -\- 0.02 

with the results given approximately, so as to avoid the use of frac- 
tional threads. 

The diagram shows the various sizes for both 16 and 72 threads 
per inch, and shows, among other things, the allowable difference in 
the flat surface, between the maximum tap and the minimum screw, 
this variation being from one-eighth to one sixteenth. 

The minimum tap conforms to the basic standard in all respects, 
except diameter. The difference between the minimum tap and 
the maximum screw provides an allowance for error in pitch and 
for wear of tap in service. 

The form of tap thread shown is recommended as being stronger 
and more servictable than the so-called V-thread, but as some 
believe a strict adherence to the form shown might add to the cost of 
small taps, they have decided that taps having the correct angle 
and pitch diameter are permissible even with the V-thread. This 
will allow a large proportion of the taps now in stock to be utilized. 

The tables given by the committee were combined into the present 
compact form by the Corbin Screw Corporation. 



A. S. M. E. MACHINE SCREW DIAGRAM 



291 




ri'^fi 



292 



BOLTS, NUTS AND SCREWS 



t/3 

a 


8 

1 


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■ 


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t-IMMMI-IC^WC»C<OC0 



TAPS FOR A. S. M. E. STANDARD SCREWS 293 



If 


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O O O 


ro Lo 1>.00 On O^ '-' ^ ^ loO t^ !>. On O O m m 

0) 01 01 Ol 01 01 oOfOOOrOfOrO'^rO"*'*'^'^ 

888888888 888888.888 




g 


\0 Osroi^iOt^fOfOMiOUON TtvO vO O 00 00 •*■<:}• 
OOOOO OOO OOON M M Tj-ro^^O OO <N r^ ro 
'^ iTiO r^oo C>0 M ro'^iJor^Oi-i poO t^ Qn <>' coO 
OOOOOOMMMMrHMi-iCqcqfNCSC^rororo 




p 

5 


o o o 


01 CO On 't '^ OO 01 t^OO ON ON r^OO GO rO oo 
t^NO nO NO NO OnOO 00 M OnO OnO vooiOO ooOn 
r^co ON O >-> 01 ro Tf Jr^CO m oDuot-^ONM roio 
OOOi-iiHMMi-ii-ii-ioioioioioirorooo 




en 

Q 
£1 


S 


o o o 
o o o 


w 01 oo Tt- ''t '^ lONO t< J>-00 00 00 O O O M M 

8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 § 




S 

s 


00 w t^ CnO O O^OO O m ^m in C^OO -^-^OOOO 
roO 00 O M (N '^ irjOO O^MvOoO C) LOM rOLOM m t^ 
ir)\0 t-~00 O i-i f^ rO'^iOt^ONM rfO Onw coO 00 O 

OOOOMMMMHMMIHCN(N(NCNrOrOfOfO'^ 


■ 


E 

a 

'5 


C>0 OOoOOC4toiOfD '^l^fO'* '^CO -* rj- t^ 1^ 
CN ir> t^oO CN i-i CO '^ t— 00 O "'to O roONiH fOOnOnio 
ir;vO t^OO Oi-< «^ ro-^vot^ONn ^OoO m roi01>.0 
OOOOOi-i»-ii-iMMi-ii-(M(N<N(NrDfOf~OrO'^ 




< 

Q 
w 





c 

1 

5 


rO lO t-^ 

CN (N N 

O O O 
O O O 


M VOOO M -^tJ-OnOInO 01 t^Ol 01 OOCOOXOO 
rntf^ro^-t^^-^ lonO vO t^ t^OO 00 00 On On 
0(50000000000000000 

oooooooooooooooooo 





E 

3 
S 

1 


O] XT-, CO 

vO r-CO 

o o o 


rOOO M lO ON ON VOOO 01 U-) M M ONOO 00 ON ON 

rONO O <~OnO On ^oO roOO roONtooiOO iom 
O « CO "^ LTyNO 00 On 01 iJ-5 t^ O 01 LOOO O ("OnO 

MMMMMMMMOlOlOirOOOCOrO'^^'*- 




s 

3 

s 


Os H <N ro ro Tl- u-j too OOcOOOOn. OnO >-< <-< 
O ^ sr^ O roO O C^ lOOO M t^roO^OM t^'rj-O'O 01 
O r^«) O M (s ro io\0 f^ Os M "*0 Os 01 ^ r^ O oj vo 

OOOWt-IMMMI-Hh-lMNtNtNCNfOOOrOTf':!-"* 








01 TtO 00 '^OO'O 0) OOO ^w O OOOOO >*■* 
CO f^O uo't-^^'^ro'^rooi 01 01 01 oq M M M M M 

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 

O roO ON 01 inoo H Tj-l>.00 0100 '^QNO oioo ^O 
\0 t^OO On M 01 ro lovO t^ On w '^'O On 01 'T t^ On Ol lO 
OOOOMMHHMMMOlOloiOloOrOoorO'^'^ 




1 


O "-I 01 


OO '^ lONO t^OO On O 01 rtOOO O 01 ^nOOO O 

WMHIMMOlOlOlOlOirO 



294 



BOLTS, NUTS AND SCREWS 



u 
1 

Q 

s 


1 

1 


r0t^c^00<NC0(NC^J^t^0t^0 0>-if~^^-''-'CS(NO QsOO OOO CO 00 
r^Jf^^ ':tLO'+iO>J-)UO u-j^ i-OO vO !>. iJ") t^ t^OO 00 CO 00 Q~>00 O On On 

q o o q q q q q q q q q q q q q q q q q q q q q q q q 


g 

S 


t-.00 ONi^CNLOCNCN'^^t^^t^t^CN^CNOsO eOcOOOOO (NOOOO 
CI, fM tH o-'i^>f^oO w i>-0 r^roO roc) Cniow t^row t^'^ONiocNOO 
LoO t^ t^ r^ OnOO OON*-iOciojrOoi'^ fOO t^O o) -^O OnO '^n© 
0000000>HqMwMMMMh.;MMM<Ncioi<NCjrocorri 


s 

s 

s 

'3 


T+M t^t— J>.t^r^t--t^t^r^t^t^ t^OO 1^00 00 00 00 On On On ^ 

0\ ON t^ "^ O l>- fOO M -^t M t^ ^ t^ lO fDOO '^CO -^01 00 voO '^fOON 
^ u~;NO r^ t-~aO 00OnOn00mmcsm-s1-(M u~,\0 Om rotOONONt-OVO 

oooooqqqq'-^^'-j'-j'-j'^'-j'-^'-j'-^'-jf^j^f^fjN'^f^ 


s 

< 
Q 

u 

< 

o 


S 


vOt^ONM C^ >-> <N N rOfO'i-ro-^ '^O pOnO OoOOO OnOnO Onm O O 

MlHM(N<N(N(N0)(N<NCI(N(N(N<NC^(N(N(N<N(N(NrOCNrOrO<^ 

ooooooooooooooooooooooooooo 
o o o q q q q q q q q q q q q q q q q q q q q q q q q 




On ^ lOOO OO t-~t^'^t^-^rDONl>-aNONVouoONON'^ OnO ■* "^ 
M rtuiLO^X t^O t^O On<^<n tOONON<NCO ONLOt^fOlOlOM COON 
NO r--C0 OCnO O CI M roo) •^^•^u-)'^NONO00 O (^ UOOO O ro LDOO o 

OOOOOWMMMMMMMMMMMM(N(N<NWrOrOrOrOTj- 


.6 
S 

1 

s 




(NT, t^vO r~~00 t^oO oO'^'^O^OONrO'+roccr-.t^ 's|- lO^^'t 
w o roroi-iO '^r-. looo r-M O m t--r--ONONO C) mM cn ro«2 O vO 
O r^C/D OnOnO O m m in (n ^'^lyo-ri-ONOoO O <^ lt-.OO O ro ^00 O 
O O O O O w M M M M M M M M M M M M (N (Ni (N cj CO rp rp ro 't 


(N tooO cs ^ oi ^ -"i- t-> t^oo r^oo CO N t^cs mOnooOOO OoO m O O 
rOCOcO"+"^'t'^'*^'t'i-'^'i-'+»0^-uouou->LOU-> lovO uoO nO O 

§ 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 2 8 8 8 8 8 8 


s 

6 

g 
5 
B 

S 

i 


roO On <N f^ 'J^ LOOO 00 M w ^^J>.1>.0 OO c^CO -^OO NOO '^O 
t-^CO Onh »-* <N Ol coroiO ij-;NO MD l>.t^ONONi-i ^nO CnC^ rJ-t^O^C^ ir^ 

OOOMMMMMWWMWMMMMMNCNC^^CNrOfOCOrO'^'^t 


OO VOMOOOOONOO rorOO) roC) OJOO COOO 00 ^ ^ <N (N <N 00 
CN IN 1>.>1 ?^ d O. CO ^O NO OnOnC^ « lo-sfQNO C^OO 'tONC woo '^t- 
NOi^ O^ O O C^ 01 CO rO -* ^ lO LO t^ t-OO OO M COO 00 m t^ O O ^ -t 

OOOMHWMMMMMMWMMMMINOlCJCSrOCpCOCO'^'^ 


1 — 


O 


•d-O 00 OO OOO c^ M O M O O ^<N it'^aOoOOOOOO ^hO o 
OLOTt^CO'^tCOCOCOCOCOCOCOtjON cO<N (N CN (N m m m m m m m 

COO OnC) lo 00 M Tt 1^ O OcNOO-^OOdOO'^fG 
t>-00 Onm c-i cowjO t^ONM -^O On 01 T}- r^ ON N to 
DOOM M *-< ^-< ^-l i-J '-', <N C) CJ 01 CO cp CO CO rj- Tt 


d 


Hc^co^ too t-co ON o ^ ^■'S'^ g S ^^"S ^ 



TAPS FOR A. S. M. E. SPECIAL SCREWS 295 



U ID 



OOOOOOOMMMMMMMMMM 



oooooooooooooogooooo 
o o o o q q q q q q q q 



ooooooqq 



cspot^t-**^'^'^'^'-' '-' ^^ 



M <N (vjOvOOOoOO TfcO 00 



SS g^i'f S^ S ^'2^ ^'%^ Scj£-^1 ?5Rgrs;s 



M M O) CM a 



CO c<o ro <^ 






M M W 



^ ^ ^ ^ '^ iJ^ ^><> ^^"^ o t^ 10 r^ t^oo 00 



000000000 
0000000 qq 















i_i 










n 


(N 


(N 


N 


w 







n 

















q 


q 


q 


q 


U 


q 






M t^ vo OnO O CnOO 00 vO 00 ^O U-, T^C0 3" ■* 2. ^°° ^ ^°S.^ Si S 

I^vO 00 00 w On C^ O ro (N O lOCO rO(N\0 2.'^2;^^5'^ '^-'^ ^ 
O r^oo O ON i-i O <N CI 

OOOOOMMMM 



_ t>,rOl>-t~-'5j--*OOoO'+OOt^'^;* 

rt U">^ t^lod00nCN<NI-'lO^VOHMTt-0 






O J>-00 o •-< O 
00000 



t-^ O lO t^ t^ ro uo 

fo CO t}- -^ 10 10 t^vO On M ro lOOO O fO toOO Ht 

MMMHMMMlHH(N<NN<NrOfDCOfO-* 



i>^Mi/^M "^M TtTj-o\a\<N onn w n on<n n w <n 0000 0000000 
^J1^^3:!5-55^!#io4 loio^o -^vo vo t^r-co c5 CO 00 o^oo 00 
nnnooOOOOOOOOOOOOOOOOOOOOOO 

o o o o o o o o o o o o o o q q q q q q q q q O q 



00 <^,oO IT) On IJO On On 10 i^-OO IJ";00 00 ^ ^ _^ 

oo^-jM'-;'^'^'^'^'^ 



M On OnOO On OnOO CO 

_ _ t^ <r> ON NO i-i On -^ O 

f— C^ 00 OnOnCN Lot^O CM \r.QO O <^nO 

H-i M (N C) CNj rorOrOfO'*'^'^ 



r-~oO 

O 



N rorf-iO'+iJOi-ONONONONONOvOoONOoOoO OnOnOnOn ^n^,^ . 
rl O ^ r^NO NO On On C) (N uo ^^,QO OO « ^ r-roONiOMC^rOONO c^ 
i^ O M M CM CM ro ro lO voNO nO r- t^ On On w rtO On cm tj- t- O £J_ if" 






^NO 000NOONONO<N<N0(NO0'^CMTfTt-000000NOc0 '^l-O NO 

NO <J->% ^,^^^'^'^':pfr><^<^'^'^ <JOW C^ CN (N M M M M M M M 



rONO On cm 
r^CO On t-i 
O O O t-J 



« CO ■* 



00 



NO CI 00 '^OnO c^oO "^O 

M ^NO OnCM -^t^ONCM U-i 

N CM N CM cocoroco'*'^ 



r)-NO CO O CI tI-nO 00 O 

MMWCNlNCiCMClCCi 



296 



BOLTS. NUTS AND SCREWS 



PROPORTIONS OF MACHINE SCREW HEADS 
A. S. M. E. Standard 

The four standard heads are given herewith. These proportions 
are based on and include the diameter of the screw, diameter of the 
head, thickness of head, width and depth of slot, radius for round 
and fillister heads, and included angle of the flat-head screw. 

Oval Fillister Head Machine Screws. A. S. M. E. Standard 



OVAL fillister HEAD SCREWS 

A = Diameter of Body. 

B = 1.64^ — .009 = Diam. of Head and 

Rad. for Oval 
C = 0.66^ — .002 = Hight of Side 
V = .173^ + .015 
^ = li? = Depth of Slot 
F = .134B + C = Hight of Head. 



-^D^ 



^- 


-n,rTs; 


— f - 


m.i. / 

! ^ 


4t 


— 




-- ► 





A 


B 


C 


D 


E 


F 


.060 


.0894 


.0376 


.025 


.025 


.0496 


'<^1Z 


.1107 


.0461 


.028 


.030 


.0609 


.086 


.132 


.0548 


.030 


.036 


.0725 


.099 


•153 


.0633 


.032 


.042 


.0838 


,112 


•1747 


.0719 


•034 


.048 


•0953 


.125 


.196 


.0805 


'^Z1 


•053 


.1068 


.138 


.217 


.089 


•039 


•059 


.1180 


•151 


.2386 


.0976 


.041 


.065 


.1296 


.164 


•2599 


.1062 


.043 


.071 


.1410 


.177 


.2813 


.1148 


.046 


.076 


.1524 


.190 


.3026 


.1234 


.048 


.082 


.1639 


.216 


•3452 


.1405 


.052 


•093 


.1868 


.242 


.3879 


.1577 


-'^^l 


.105 


.2097 


.268 


•4305 


.1748 


.061 


.116 


•2325 


.294 


•4731 


.192 


.066 


.128 


•2554 


.320 


.5158 


.2092 


.070 


.140 


.2783 


.346 


.5584 


.2263 


•075 


.150 


.3011 


•372 


.601 


•2435 


.079 


.162 


.3240 


.398 


•6437 


.2606 


.084 


•173 


.3469 


.424 


.6863 


.2778 


.088 


.185 


.3698 


.450 


.727 


•295 


•093 


.201 


.4024 



FLAT FILLISTER HEAD MACHINE SCREWS 297 
Flat Fillister Head Machine Screws. A. S. M, E. Standard 



FLAT FILLISTER HEAD SCREWS 

A = Diameter of Body 
B = 1. 64 A — .009 = Diam. of Head, 
C = 0.66A — .002 = Hight of Head 
D = 0.173^ + .015 = Width of Slot 
E = ^C = Depth of Slot 



-B ^ 



I — HD;- 



bZUT 

I 



^.-4a-> 



A 


B 


C 


D 


E 


.060 


.0894 


.0376 


.025 


.019 


.073 


.1107 


.0461 


.028 


.023 


.086 


.132 


.0548 


.030 


.027 


.099 


.153 


.0633 


.032 


.032 


.112 


.1747 


.0719 


•034 


.036 


.125 


.196 


.0805 


•037 


.040 


.138 


.217 


.0890 


•039 


.044 


•151 


.2386 


.0976 


.041 


.049 


.164 


•2599 


.1062 


.043 


.053 


.177 


.2813 


.1148 


.046 


•057 


.190 


.3026 


.1234 


.048 


.062 


.216 


•3452 


.1405 


.052 


.070 


.242 


.3879 


•1577 


•057 


.079 


.268 


•4305 


.1748 


.061 


.087 


.294 


•4731 


.1920 


.066 


.096 


.320 


.5158 


.2092 


.070 


.104 


.346 


•5584 


.2263 


•075 


.113 


•372 


.601 


•2435 


.079 


.122 


•398 


•6437 


.2606 


.084 


.130 


424 


.6863 


.2778 


.088 


.139 


.450 


•727 


•29s 


•093 


.147 



298 BOLTS. NUTS AND SCREWS 

Flat Head Machine Screws. A. S. M. E. Standard 



FLAT HEAD SCREWS 

A = Diameter of Body 

B = 2A — .008 = Diam. of Head 

C = ■ ~ '°° = Depth of Head 

1.739 
D = .173^ + .015 = Width of Slot 
E = IC = Depth of Slot 



.J2-Deg.- 



^^ 



iV 



\ 


-^t'rr 


\' 


^ 


/{ 




, A-— 





A 


B 


c 


D 


1 

E 


.060 


,112 


1 

.029 


.025 


I ^10 


•073 


.138 


j '^21 


.028 


1 .012 


.086 


.164 


.045 


.030 


1 .015 


.099 


.190 


.052 


.032 


.017 


.112 


.216 


.060 


.034 


' .020 


.125 


.242 


.067 


«o37 


, .022 


.138 


.262 


.075 


•039 


.025 


•151 


.294 


.082 


.041 


.027 


.164 


.320 


.090 


.043 


.030 


.177 


.346 


.097 


.046 


.032 


.190 


•372 


.105 


.048 


'03S 


.216 


.424 


.120 


.052 


.040 


.242 


.472 


•135 


•057 


.045 


.268 


.528 


.150 


.061 


.050 


.294 


.580 


.164 


.066 


.055 


.320 


.632 


.179 


.070 


.060 


.346 


.682 


.194 


'OlS 


.065 


.372 


:732 


.209 


.079 


.070 


•398 


.788 


.224 


.084 


.075 


.424 


.840 


•239 


.088 


.080 


450 


.892 


.254 


•093 


.085 



ROUND HEAD MACHINE SCREWS 299 

Round Head Machine Screws. A. S. M. E, Standard 



ROUND HEAD SCREWS 
A — Diameter of Body 
B = i.S^A — .005 = Diam. of Head 
C = .yA = Hight of Head 
D = .173^ + .015 = Width of Slot 
£ = JC + .01 = Depth of Slot 




A 


B 


c 


D 


! 

E 


.060 


.106 


.042 


.025 


.031 


.073' 


.130 


.051 


.028 


•035 


.086 


•154 


.060 


.030 


.040 


.099 


.178 


.069 


.032 


.044 


.112 


.202 


.078 


.034 


.049 


.125 


.226 


.087 


•037 


•053 


.138 


.250 


.096 


•039 


.058 


•151 


.274 


.105 


.041 


.062 


.164 


.298 


.114 


.043 


.067 


.177 


.322 


.123 


.046 


.071 


.190 


.346 


•^33 


.048 


.076 • 


.216 


•394 


•151 


.052 


.085 


.242 


.443 


.169 


•057 


.094 


.268 


.491 


.187 


.061 


.103 


.294 


•539 


.205 


.066 


.112 


.320 


•587 


.224 


.070 


.122 


.346 


.635 


.242 


•075 


•131 


.372 


.683 


.260 


.079 


.140 


.398 


•731 


.278 


.084 


.149 


.424 


•779 


.296 


.088 


.158 


•450 


.827 


•315 


•093 


.167 



300 



BOLTS, NUTS AND SCREWS 





Hot Pressed and Cold Punched Nuts 



U. S. Standard Hot Pressed and 
Cold Punched Nuts 


Cold Punched Check and 


[am Nuts 


HEXAGON AND SQUARE 


HEXAGON 


Dia. 


Across 


Thick- 


Dia. 


Dia. 


Across 


Thick- 


Dia. 


Bolt 


Flats 


ness 


Hole 


Bolt 


Flats 


ness 


Hole 


1 


. 


1 

4 


^ 


\ 


1 


tV 


if 


T^ 


if 


t\ 


i 




if 


7 
■32 


i 


f 


16 


f 


9 


f 


H 




H 


f^ 


11 


tV 


-i 


tV 


fl 


A 


il 


h 


1 


h 


il 


h 




A 


M 


A 


M 


T% 


If 


tV 


fi 


M 


If 


•L 


itV 


f 


f 1 


f 


ItV 




If 


1 


li 


f 


1 




li 


tV 


1 


1 


ItV 


i 


a 


I 


ItV 


i 


11 




If 




H 




If 


tV 


H 


li 


III 


li 


if 


ll 


iH 


1 


if 




2 




ItV 


li 


2 


f 


ItV 


if 


2t\ 




lA 


if 


2tV 


V 


I/^ 


jl 


2| 


l| 


lA 


li 


2i 




13% 


If 


2t% 


If 


iM 


If 


2tV 


If 


III 


if 


2| 


If 


li 


if 


2f 


I 


ll 


l| 


2M 


l| 


If 


ij 


2l| 


irV 


if 


2 


3l 


2 


Iff 


2 


31 


li 


Iff 


2l 


3T6 


4 


lit 










H 


3l 


2i 


iM 










2| 


3H 


2| 


2tV 










2* 


3i 


2i 


2ii 










21 


4i 


2f 


2|| 










3 


4l 


3 


2f 











Finished case-hardened and semi-finished nuts are made to the 
above dimensions. Semi-finished nuts are tapped and faced true 
on the bottom. 



HOT PRESSED NUTS 



301 





Hot Pressed Nuts 



Hot Pressed Nuts, Manufacturers 


Hot Pressed and Forged Nuts. Manufac- 




Standard 




turers Standard 




HEXAGON 


Square 


Dia. 


Across 


Thick- 


Dia. 


Dia. 


Across 


Thick- 


Dia. 


Bolt 


Flats 


ness 


Hole 


Bolt 


Flats 


ness 


Hole 


i 


f 


i 


3^ 


i 


1 


i 


s\ 


t\ 




A 


-,% 


F 


1 


T% 


■i^ 


f 


f 


1 


H 




f 


f 


ih 


T^ 


1 


tV 


II 


tV 


1 


7 
T^ 


If 


h 


I 


i 


tV 


i 


^ 


i 


tV 


F 


i| 


9 
T6 


I 


t\ 


li 


t\ 


1 


f 


I4 


f 


^ 


1 


li 


1 




f 


if 




u 


f 


I* 


f 


II 


1 


Is 


1 


li 


1 


If 


i 


II 


I 


^4 


I 


i 


I 


2 


I 


i 


ij 


2 


li 


li 


ll 


24 


Ij 


II 


I? 


2i 


If 


l3\ 


Ij 


2J 


li 


l3\ 


if 


22 


li 


lA 


if 


2f 


if 


it\ 


i| 


2| 


if 


it\ 


I* 


3 


I| 


Il% 


i| 


3 


if 


itV 


If 


3i 


I| 


IT% 


If 


3i 


l| 


It\ 


if 


3i 


If 


IT^ 


li 


3^ 


2 


IH 


li 


3f 


l| 


ill 


2 


3i 


2 


III 


2 


4 


2 


I If 


2j 


3f 


21- 


ll 


2g- 


4 


2i 


l| 


2i 


3f 


21 


2 


2? 


4i 


2i 


2 


2i 


4 


2| 


2j 


2| . 


4i 


2i 


2i 


22 


4i • 


2^ 


2i 


2^ 


4i 


2i 


2-1 


2| 


42 


2f 


2t^^ 


2f 


4f 


2f 


2-(T. 


3, 


4f 


3 


2-i 


3 


5 


3 


2-6 


3i 


5 


3i 


2-| 


3i 


5i 


3i 


2-6 


3§ 


5i 


3i 


3h 


32 


6 


3i 


3i 



302 



BOLTS, NUTS AND SCREWS 





Cold Punched Nuts, Manufacturers Standard 



Hexagon 


Square 


Dia. 


Across 


Thick- 


Dia. 


Dia. 


Across 


Thick- 


Dia. 


Bolt 


Flats 


ness 


Hole 


Bolt 


Flats 


ness 


Hole 


\ 


f 


i 


^2 


i 


J 


i 


# 


l\ 






1% 


T% 


f 


A 




1 


1 


1 


j' 


f 


3 

4 


f 


M 


1^6 


1 


T5 


13 


f. 


1 


^ 


M 


1 


1 


^ 




i 


i 


tV 


i 


I 


1 


t\ 


1 




i 


tV 


i 


I 


A 


T6 


A 


l| 


p- 


i 




li 


t\ 


i 


1 


l| 




A 


F 


li 


1 


T^ 


f 




f 


A 


1 


Ii 


1 


♦ 






1 


M 


1 


li 


f 




f 


If 


f 


H 


1 


if 




|1 


1 




1. 


If 


1 


if 


1 


f^ 


1 


if 


7 




■ ■ 


I* 


1 


^1 


1 


if 


1 


If 


y 


l| 


^ 


2 1 
¥2 




If 




i: 


•■ 


I* 


i 


1* 




2 




i 


1 


4 


I 


25 


Ij 


2 


Is 


1 5 
T6 


1 


If 


1 


II 


l| 


2i 


l| 


M 


1 


if 




ft 


If 


2l 


Ii 


ItV 




If 








2^ 


^4 


itV 




If 


Ij 


1 


if 


2f 


if 


IT% 


li 


2 


Ii 


\l 


I^ 


3 


li 


^¥ 


If 


2i 


If 


lT^6 


if 


3i 


If 


'<^ 




2i 


li 


If^ 


If 


3* 


if 


It\ 


4 


2f 


i| 


IT% 


. li 


3f 


l| 


iH 


If 


3 


If 


II'. 


2 


4 


2 


iH 




3i 


i| 


il^e- 










ii 


3i 


2 


li^ 










2 


3i 


2 


lyl 










2 


3l 


2i 


III 











HOT PRESSED NUTS 



303 





Hot Pressed Nuts. Manufacturers Standard Narrow Gage Sizes 




Dimensions of Whitworth Standard Hexagonal Nuts and Bolt-Heads 



Dia. 
of 
Bolt 


Width of X 

Nut or Bolt ^ 

Head across pi 

Flats ^°^ 


ligbt 
of 
t Head 


Dia. 

of 
Bolt 


Width of 

Nut or Bolt 

Head across 

Flats 


Hight 

of 

Bolt Head 


i 


.338 


109 


li 


2.048 


1.094 


^^® 


•448 


164 


if 


2.215 


1.203 


i 


•525 


219 


i^ 


2.413 


1.312 


A 


.601 


273 


if 


2.576 


1.422 


1 


.709 


328 


if 


2.758 


I-53I 


V- 


.820 


383 


If 


3-018 


1. 641 


h 


.919 


437 


2 


3149 


I-750 


1% 


I. on 


492 


2| 


3-337 


1-859 


f 


I.IOI 


547 


2i 


3-546 


1.969 


H 


1. 201 


601 


25 


3-750 


2.078 




1. 301 


656 


2i 


3-894 


2.187 


U 


1.390 


711 


2- 


4-049 


2.297 


I 


1.479 


766 


2f 


4.181 


2.406 


it 


I-S74 


820 


2S 


4-346 


2.516 


1 


1.670 


87s 


3 


4-531 


2.625 


i| 


1.860 


984 









304 



BOLTS, NUTS AND SCREWS 




Button Head Machine and Loom Bolts 

HOOPES & TOWNSEI^ Co. 



Diameter Bolt. . 


t\ 


1 

4 


A 


f 


tV 


h 


fk 


. 


•3. 


1 


I 


Diameter Head . 


4 


t 


H 


i^ 


itV 


I^ 


ifV 


if 


if 


l| 


2k 


Thickness of 
























Head 


s\ 


1 


/i 


t\ 


i 


1 

4 


A 


f 


h 


f 


f 



Carriage Bolts 
Upson Nut Co. 



Diameter Bolt. . 


t\ 


1 

4 


^ 


f 


% 


i 


A 


f 


1 


f 


I 


Diameter Head . 


t\ 


f*^ 


H 


H 


ItV 


ItV 


lA 


ir'e 


iH 


2t\ 


Thickness of 
























Head 


A 


i 


i-. 


-1% 


s\ 


1 

4 


3\ 


/. 


' 


t\ 


^ 



LENGTHS OF BOLTS 

Square Head, Hexagon Head, Button Head, Round Head and 
Cone Head bolts are measured under the head. Countersunk 
Head bolts, bolt ends and rods are measured over all. 

Lengths of Threads Cut on Bolts 



Length of Bol 


ts i & A 


!&/. 


l&i% 


1 


f 


1 


I 


li 


li 


I to iV 


.. f 


1 




li 












if to 2 " 


8 


I 




li 


li 


if 








2|tO 2i" 




I 




li 


li 


If 


If 






2f to 3 " 




I 




li 


I? 


I4 


2 


2i 




3l to 4 " 




li 


J^4 


li 


li 


if 


2 


2i 


2i 


4i to 8 " 




li 




li 


I? 


2 


^1 


2f 


3. 


81 to 12 " 




li 


I^ 


If 


2 


2i 


3. 


■4 


12^ to 20 " 




i^ 


2 


2 


2 


2i 


3 


3i 


3i 



Bolts longer than 20 inches and larger than ij inch in diameter 
are usually threaded about 3 times the diameter of the rod. 



MACHINE AND TAP BOLTS 



305 





Round and Square Countersunk Head Bolts 



Diameter Bolt 

Diameter Round Head .... 
Distance across Flats Square 

Head 

Thickness Square and 

Round Heads 







i 


It 


¥ 


ft 


4 


1 


1 


h 


if 


H 


ft 


1 


11 


13^ 


li 


ii^ 


A 


t\ 


-h 


i 


i 


3% 


A 


H 


M 



Tap Bolts 





Diameter Bolt 

No. of Threads per Inch . . . 
Across Flats Hex. and Square 

Heads 

Across Comers Hex. Head . 
Across Comers Square Head 
Thickness Hex. and Square 

Heads 



i 


T^^ 


f 


t\ 


i 


T% 


f 


f 


1 


20 


18 


16 


14 


13 


12 


II 


10 


9 


f 


M 


A 


U 


f 


n 


H 


li 


lA 


T^ 




T2 


3 
4 


n 


M 


I.v 


Hf 


iM 


i-i 


U 


H 


it 


II^ 


ItV 


Ili 


iH 


4f 


A 


i 


A 


1 


tV 


§ 


H 


1 


f 



li 

2i 



Stove Bolt Diameters and Threads 



(^ 



Dia. of Bolt 

No. of Threads per Inch , 



i 


-,% 


A 


aV 


i 


tV 


32 


28 


24 


22 


18 


18 



3o6 



BOLTS, NUTS AND SCREWS 




Eefers to all Nuts 
and Screw Heads, 
d =Dia. Cotter Pin 



Hr 



t— a-* 




K-H-i 



DX 1.5 Length of Thread 
P^Pitch of Thread 
-|-=Flat 



All heads and nuts to be semi-finished. All screws to be of steel 
not less than 100,000 pounds tensile strength and 60,000 pounds 
elastic limit per square inch. Screws, screw heads and plain nuts 
to be left soft. Castle nuts to be case-hardened. Where screws 
are to be used in soft material such as cast iron, brass, bronze or 
aluminum, the U. S. S. pitches are to be used. Body diameter to 
be o.ooi inch less than nominal diameter with a plus tolerance of 
zero and a minus tolerance of 0.002 inch. Nuts shall fit without 
perceptible shake. This was originally known as the A. L. A. M. 
Standard, but is now the S. A. E. (Society Automobile Engineers). 



Automobile Screw 


AND 


Nut Stand 


\RDS Adopted by the S. 


A. E. 


D 


i 


A 


f 


A 


h 


9 

T6 


f 


ii 


1 


7 

8 


I 


P 


28 


24 


24 


20 


20 


18 


18 


16 


16 


14 


14 


A 


z% 


M 


if 


II 


T% 


n 


If 


fl 


if 


If 


I 


a 


/^ 


U 


u 


f 


tV 


u 


If 


if 


B 


If 


1 


B 


tV 


h 


T% 


1 


f 


1 

8 


if 


I 


ItV 


li 


ItV 


C 


A 


j\ 


i 


1 

8 


t\ 


t\ 


\ 


i 


i 


1 
4 


1 
4 


E 


5 

6? 


-i^ 


1 


^ 


i 


z\ 


h 


A 


A 


A 


3^^ 


H 


t\ 


if 


j% 


u 


1 


II 


if 


If 


T^e 


If 


3 
4 


I 


^ 


^V 


i 


i 


i 


\ 


1 


i 


i 


i 


i 


K 


IV 


t\ 


A 


A 


A 


3^- 


3\ 


A 


A 


3\ 


3^ 


d 


-h 


tV 


aV 


-i-2 


A 


i 


i 


i 


i 


i 


i 


L 


t 


if 


A 


V. 


f 


H 


H 


lA 


li 


It\ 


i^ 



BOLTS AND NUTS 

Planer Nuts 



307 



Diameter of Bolt 

No. of Threads per Inch 

Across Flats 

Thickness 



h 


f 


1 


i 


I 


i|- 


11 


II 


10 





8 


7 


I 


ItV 


li 


^i\ 


If 


III 


{'i 


I 


I J 


itV 


lA 


If 



li 

7 
2 

2t^^ 



Coupling Bolts 



^CJ 



n 



Diameter of Bolt 

No. of Threads per Inch 
Short Diameter of Head 

Length of Head 

Thickness of Nut 

Short Diameter of Nut . 



i 


f 


f 


I 


I 


a 


^-^ 


II 


10 


Q 


8 


7 


1 


ItV 


li 


itV 


i| 


1^1 


h 


t 






I 


I* 


h 


t 


f 


^ 


I 


I* 


I 


ItV 


li 


il'e 


i^ 


iH 



Planer Head Bolts and Nuts 



C 




D rT^~T 1 





Diameter of Bolt 

No. of Threads per Inch 

Short Diameter of Head 

Length of Head 

Short Diameter of Nuts 

Thickness of Nuts 

Washers for Planer Head Bolts, 

Diameter of Washers 

Thickness of Washers 



h 


t\ 


1 


H 


12 


12 


12 


12 


I 


I 


ij 


li 


t\ 


fV 


1 


f 


I* 


li 


li 


li 


1 


i 


■i 


'i 


h 


1^6 


i 


H 


I^ 


It'. 


A 


ii^ 


T^^ 


tV 


t'-z 


rV 



III 

3\ 



3o8 BOLTS, NUTS AND SCREWS 

Depths to Drill and Tap for Studs 




Dia. of Stud 

Dia. of Drill C. I. 
Depth of Thread. 
Depth to Drill 



A 


} 


^ 


1 


t\ 


^ 


1% 


f 


1 


^ 


B 


H 


H 


5 


i 


u 


6 4 


-f 


fi 


f 


C 


* 


r?, 


1^ 


H 


i 


H 


-t 


li 


IT^W 


D 


r'l 


7 
'3"2 


1 


IS 


H 


it 


l3^2 


li 


1X^6 



I 

5 5 
If 



Bolt Heads for Standard T-Slots 

I ■ 





B 



Dia. 


Width 


Thickness 


Width 


Width 


Depth 


Maximum 


of 


of 


of 


of 


of 


of 


Depth with 


Bolt 


Head 


Head 


Slot 


Slot 


Slot 


St'd Cutter 


A 


B 


C 


D 


E 


F 


G 


1 

4 


T6 


i 


f\ 


f 


^2 


f 


5 
T6 


^ 


1% 


f 


H 


3\ 


i\ 


f 




1^ 


T6 


H 


j'j. 


T6 


t\ 








It 


_9_ 


T% 


i 


li 


1 


1 


ItV 


-1 


f 


f 


li 


^ 


f 


^rs 


-1 


I 


1- 


'tV 


t 


7 
8 


I f 


-i 


1X^6 


i 


lit 


f 


I 


I 1 


it 


ixV 



EYE BOLTS AND COTTER PINS 



309 




Eye Bolts 



A 


B 


C 


D 


E 


F 


G 


f 


2 


1 


7 


A 


1 


T% 


h 


2* 


I 




i 


h 




f 


2i 


li 


li- 


A 


1 


^ 




2I 


lT6 




t\ 


ii 


■t% 


1 


2i 


iH 


lt 


i 


1 


1 




2f 


li 




re 


i 


4 


l| 


2| 


2 J 


l| 






if 




3 


2 1 




^ 


li 


i 


if 


3l 


2i 


ij 


T% 


lA 


I 


I^ 


3i 


2f 


2 


f 




ItV 


if 


3l 


3 


2i 


ii 


I f 


li 


if 


3i 


3i 


2-;: 


f 


i^ 


li 


l| 


3f 


3h 


25 


if 


If 


lA 


2 


3f 


3f 


2i 


1 


If 


If 



Spring Cotters 




No. of Wire Gage 


it0 2 


12 

it0 2 


II 

Jt0 2i 


i£. 


jij 


ii 


7 
f t0 3 


6 


Dia. Inches 


1^3 






No. of Wire Gage 


5 
I to 3 


4 
I to 4 


I 




2 to 6 


f 
3 to 6 





















Regular Lengths vary by J inch up to 4 inches and by i inch from 4 to 6 inches. 
Lengths are measured under the eye. 



3IO 



BOLTS, NUTS AND SCREWS 



Round ai-jd Square Washers 




U. S. Standard Washers 



Size of 
Bolt 


Size of 
Hole 


Outside 
Diam- 
eter 


A 


i 


A 


i 


A 


3 
4 


A 


1 


i 


f 


tV 


I 


tV 


i 


li 


h 


A 


If 


T% 


f 


li 


f 


H 


If 


f 


it 


2 


1 


if 


2i 




ItV 


2i 


I| 


li 


2f 


li 


If 


3 


If 


li 


3i 


li 


If 


3i 


If 


If 


3f 


If 


i| 


4 


l| 


2 


4i 


2 


2i 


4i 


2i 


2f 


4l 


2^ 


2f 


5 



Thickness 

Wire Gage 

No. 



l8 (A) 
i6 (tV) 
i6 (A) 
14 (e\) 
14 (/t) 
12 (^,) 
12 (j\) 
io(i) 
io(i ) 
9 (/o) 
9(^) 

9 (3\) 

9 (A) 
8 (iD 

sai) 

8(H) 
8(ii) 
8 (ii) 
8(H) 
6(A) 

5(3^) 



Narrow Gage Washers 



Size of 
Bolt 


Size of 
Hole 


Outside 
Diam- 
eter 


i 


A 


5 

8 


A 


f 


f 


§ 


A 


7 


A 


^ 


I* 


i 


A 


li 




^ 


if 


f 


-| 


li 


1 


T6 


If 


^ 


-l 


2 




lA 


2i 


li 


li 


2-^ 




if 


2f 


if 


li 


3 


li 


if 


3i 



Thickness 

Wire Gage 

No. 



l6 (A) 

l6 (A) 

l6 (A) 

14 (6\) 

12 (A) 
12 (A) 

loa ) 
loa) 

9 (A) 



9 (A) 

8(H) 
8(H) 



Square Washers 
standard sizes 



Size of 
Bolt 


Size of 
Hole 


Width 


f 


A 


li 


A 


^ 


If 


1 


A 


2 


f 


11 


2i 


f 


|4 


2* 


1 


H 


3 


I 


lA 


3+ 


li 




4 


li 


ig 


4i 


If 


I* 


5 


i^ 




6 


if 


i| 


6 


2 


2? 


6 



Thickness 



1 



WASHERS AND SCREW GAGE 



311 




Cast-Iron Washers 



Size of 
Bolt 


Outside 
Diameter 


Thickness 


Size of 
Bolt 


Outside 
Diameter 


Thickness 


t 


li 


■h 


li 


4i 




h 


2 


i 




5 


ij 


i 


2i 


I 




Sh 


I 




3 


1 


l| 


6 


If 


1 


3i 


f 


I4 


7 


li 


I 


' 


i 


2 


7i 


If 



Riveting Washers 



Size 

of 

Rivet 


Size 

of 

Hole 


Outside 
Diam- 
eter 


Thick- 
ness 


Size 

of 

Rivet 


Size of 


Outside 


Thickness 


Wire 
Gage 


Hole 


Diameter 


Wire Gag 


7 (.180) 


fV 


* 


18 


1 


M 


li 


12 


6 (.203) 


i2 


tHt 


18 


T^^ 


M 


I 


14 


5 (-220) 


n 


^ 


18 


t'« 


M 


I4 


12 


i 




1 


16 


* 


ii 


Is 


12 


i 


7 




16 


* 


il 


li 


12 


A 


-^ 


1 


14 


1 


}l 


l| 


II 


T% 




1 


14 


f 


II 


l§ 


JI 




^|- 


1 


14 


^ 


fi 


If 


10 


f 


-0 2^ 


I 


14 











Machine and Wood Screw Gage 



No. of 


Size of 


No. of 


Size of 


No. of 


Size of 


No. of 


Size of 


Screw 


Number in. 


Screw 


Number in 


Screw 


Number in 


Screw 


Number in 


Gage 


Decimals 


Gage 


Decimals 


Gage 


Decimals 


Gage 


Decimals 


000 


.03152 


12 


.21576 


25 


.38684 


38 


•55792 


00 


.04468 


13 


.22892 


26 


.40000 


39 


•57108 





.05784 


14 


.24208 


27 


.41316 


40 


.58424 


I 


.07100 


15 


25524 


28 


.42632 


41 


•59740 


2 


.08416 


16 


.26840 


29 


.43948 


42 


.61056 


3 


■OQ732 


17 


.28156 


30 


•45264 


43 


.62372 


4 


.11048 


18 


.29472 


31 


.46580 


44 


.63688 


5 


.12364 


19 


.30788 


32 


.47896 


45 


.65004 


6 


.13680 


20 


.32104 


33 


.49212 


46 


.66320 


7 


.14996 


21 


•33420 


34 


.50528 


47 


.67636 


8 


.16312 


22 


•34736 


35 


.51844 


48 


.68952 


9 


.17628 


23 


.36052 


36 


.53160 


49 


.70268 


10 


.18944 


24 


.37368 


37 


.54476 


5° 


•71584 


II 


.20260 


The difference 


between co 


nsecutive si 


zes IS .01 


J16" 



312 



BOLTS, NUTS AND SCREWS 




Gimlet Point 



Coach and Lag Screws 



Diameter Screw 

No. of Threads per Inch . . . 
Across Flats Hex. and 

Square Heads 

Thickness Hex. and Square 

Heads 



lO 


9i 


1 
7 


7 


6 


5 


1 

5 


f 

4i 


Ah 


1 


M 


A 


fi 


1 


II 


^1 


i| 


lA 


t\ 


\ 


tV 


f 


tV 


i 


H 


1 


f 



li 



Lengths of Threads on Coach and Lag Screws 
or all diameters 



Length of Screw 


Length of Thread 


Length of Screw 


Length of Thread 


ir 


To Head 


5 " 


A" ' 


?" 


ir 


Sh" 


A" 


2Y 


2 " 


6 '' 


a¥ 


• 3" 


^Y 


7 " 


s" 


3¥ 


2^' 


8 '' 


6 " 


A" 


Z" 


9 '' 


6 " 


a¥ 


2>¥ 


lO to 12'' 


1" 



Lag-Screw Test 
(screws drawn out of yellow pine) 
Test by Hoopes and Townsend 



Diameter Screw. 
Depth in Wood 
Force in Pounds 



\m. 


tin. 


fin. 


iin. 


3iin- 


4 in. 


4 in. 


5 in. 


4,960 


6,000 


7,685 


11,500 



I m. 
6 in. 
12,620 



WOOD SCREWS 



3^3 



WOOD SCREWS 

Wood screws range in size from No. o to No. 30, by the American 
Screw Company's gage and in lengths from \ inch to 6 inches. The 
increase in length is by eights of an inch up to i inch, then by quar- 
ters of an inch up to 3 inches and by half inches up to 5 inches. As 
a rule the threaded portion is about seven tenths of the total length. 
The included angle of the flat head is 82 degrees. The table below 
gives the body and head diameters, and the threads per inch as gen- 
erally cut, although there is no fixed standard as to number of threads 
which is universally adhered to by all wood-screw manufacturers. 

Flat headed wood-screws include the head in the length given. 
With round headed screws, one half the head is generally included 
in the length although the practice is not uniform. 



r^ 

t 



Wood-Screw Dimensions 
(angle of flat head = 82 degrees) 



^ 








^ 


t 








fc 


g 








a 










a 


^ (U 


Diameter of 


Diameter of 


tn 


'^ a; 


Diameter of 


Diameter of 


-§ 


•si 


Screw 


Head 


l-s 


^^ 


Screw 


Head 


s-s 


60 








2: c5 


dO 








M>^ 


Z 








H 


2i 








H 





.05784 


tV- 


.110 


^4 + 


32 


16 


.26840 


H + 


.526 


u- 


9 


I 


.07100 


5 

64 


.136 


e\- 


28 


17 


.28156 


^% 


•552 


ff + 


9 


2 


.08416 


6^ + 


.162 


^2 + 


26 


18 


.29472 


il- 


.578 


3-1 


8 


3 


.09732 


A + 


.188 


A 


24 


19 


.30788 


A- 


.604 


If "~ 


8 


4 


.11048 


/? + 


.214 


A- 


22 


20 


.32104 


ti- 


•630 


f + 


8 


5 


.12364 


i - 


.240 


H + 


20 


21 


.33420 


li + 


.656 


fl 


8 


6 


.13680 


j\- 


.266 


k + 


18 


22 


.34736 


M + 


.682 


H- 


7 


7 


.14996 


A- 


.292 


if- 


16 


23 


.36052 


If 


.708 


lf + 


7 


8 


.16312 


A + 


.318 


A + 


15 


24 


.37368 


1 - 


•734 


11 


7 


9 


.17628 


H + 


•344 


M + 


14 


25 


.386S4 


If — 


.760 


n- 


7 


10 


.18944 


A + 


•370 


1 - 


13 


26 


.40000 


|v — 


.786 


ff + 


6 


II 


.20260 


M- 


.396 


If + 


12 


27 


.41316 


M + 


.812 


i-i 


6 


12 


.21576 


S- 


.422 


U 


II 


28 


.42632 


11 + 


.838 


11- 


6 


13 


.22892 


if- 


.448 


11- 


II 


29 


.43948 


tV + 


.864 


M + 


6 


14 


.24208 


i- 


.474 


M + 


10 


30 


.45264 


■> q 

n 


.890 


U 


6 


IS 


.25524 


i + 


.500 


i 


10 















314 



BOLTS, NUTS AND SCREWS 

U. S. Navy Boiler Rivets 






U- 



<--A ■■> 



A 


B 


c 


D 


Weight of 
10 heads 


Weight per 
inch of 
shank L 


\ 


H 


1^ 


§ 


• 531 


■ 0556 


■h 


I 


h 


A 


.713 


.0704 


f 


li 


A 


f 


1.007 


.0869 


H 


li 


f ■ 


H 


1-372 


.1052 


f 


lA 


1 


f 


1. 551 


.1251 


H 


ii^ 


H 


H 


2.033 


.1470 


1 


i^ 


H 


i 


. 2.258 


.1703 


H 


if 


3 


H 


2.871 


.1956 


I 


If 


H 


I 


3.5B4 


.2225 


1^ 


iH 


if 


lA 


3.910 


.2512 


If 


iM 


1 


li 


4.761 


.2816 


ii^ 


2 


i 


lA 


5.170 


.3137 


li 


2| 


H 


If 


6.215 


.3477 


lA 


2f 


I 


lA 


7.391 


.3833 


If 


2| 


lA 


If 


8.490 


.4207 


Irs 


2| 


li 


lA 


9.941 


.4599 


ij 


2| 


lA 


li 


11.507 


.5006 


lA 


2f 


Is 


lA 


13.242 


.5433 


If 


2| 


lA 


If 


15.146 


.5876 


iH 


3 


If 


iH 


17.300 


.6336 


If 


3i 


11% 


If 


19.485 


.6815 



U. S. Navy Hull and Tank Rr^t Heads 

I<-D-H 



PAN-HEAD 







< A > 





BUTTON 




Pan-head 




Button 






Countersunk 




A 


B 


c 


D 


A 


B 


C 


A 


B 


c 


D 




A 


A 


\ 


i 


A 


A 


\ 


I 


A 


60 




f 


A 


\ 


i 


f 


A 


\ 


f 


A 


60 




H 


f 


\ 


\ 


if 


f 


\ 


if 


\ 


60 




I 


A 


f 


\ 


I 


A 


1 


lA 


\ 


60 




lA 


\ 


f 


f 


lA 


\ 


f 


lA 


\ 


45 




lA 


A 


8 


\ 


lA 


A 


1 


lA 


ii 


45 


I 


li 


f 


I 


I 


li 


f 


I 


If 


if 


37 


li 


If 


H 


I| 


li 


If 


H 


i| 


If 


if 


37 


ij 


iH' 


f 


li 


x\ 


lit 


\ 


If 


Iff 


I 


37 



ROUND HEAD RIVETS 



315 



LENGTH OF ROUND HEAD RIVETS FOR DIFFERENT 
THICKNESSES OF METAL 

To find the required length of a rivet when tliickness of metal 
between rivet heads is given, assuming the rivet hole to be yV i^ich 
larger than the rivet before it is heated, refer to the table below. 
Grip in inches means thickness of metal between rivet heads. 





Diameter in Inches 


Grip 












in 


i 


f 


1 


1 


I 


Inches. 














Length in Inches. 


f 


i^ 


If 


i| 


2 


2i 




if 


i| 


2 


2| 


2i 


3 
4 


if 


2 


2| 


2j 


2f 


1 


l| 


2| 


2i 


2f 


2 




2 


2i 


2! 


22^ 


2; 


u 


2| 


2f 


2t 


2f 


2v 


li 


2;: 


2| 


2f 


2f 


2| 


If 


2f 




2f 


2| 


3 




2 • 


2| 


3 


3i 


31 


if 


2i- 


3 


3i 


3i 


si 


ll 


2| 


3l 


3i 


3l 


S2 


ll 


3 


si 


3l 


3l 


si 


2 


- 3l 


si 


3§ 


3l 


si 


2| 


3i 


3I 


3f 


3f 


sl 


2j 


3f 


3f 


3f 


sl 


4 


2I 


3I 


3f 


3I 


4 


4i 


2I 


4 


Si 


4 


4i 


4i 


2| 


3f 


4 


4i 


4i 


4f 


2f 


3l 


4i 


41 


4f 


4I 


2| 


4 


4i 


4- 


4I 


4f 


3, 


4i 


4| 


4f 


4f 


4l 


3I 


4t 


4-1 


4f 


4l 


5 


3l 


4l 


4f 


4l 


5 


5i 


3f 


4f 


4l 


5 


5i 


5i 


3l 


< 3 


5 


5i 


5i 


5f 


4 


4I 


5i 


4 


5f 


5I 


si 


5 


Si 


5f 


5^ 


5f 


si 


58 


5f 


4 


5f 


4 


4 


54 


5I 


5f 


5f 


5l 


41 


52 


5f 


5I 


6 


61: 


4i 


54 


6 


6i 


6f 


6| 


4f 


6- 


61 


6i 


6f 


6f 


5 


6- 


61 


6f 


61 


7 



CALIPERING AND FITTING 

THE VERNIER AND HOW TO READ IT 

This method of measuring or of dividing known distances into 
very small parts is credited to the invention of Pierre Vernier in 163 1. 
The principle is shown in Figs, i to 3 and its application in Figs. 4 
and 5. In Figs, i and 2 both distances o-i are the same but they 
are divided into different divisions. Calling 0—1 = 1 inch then in 
Fig. I it is clear that moving the lower seal one division will divide 



J^ 1 
FIG. I 



^ ^ 1 
FIG. 2 



ll 



1 I 3 
2 

FIG. 3 



I I I I 



i 1 I ^ 4 = 



FIG. 4 



4 6 

FIG. 5 



Vernier Reading 



the upper one in half. In Fig. 2 the upper scale is divided in half 
and the lower one in thirds. If the lower scale is moved either way 
until i or f comes under the end line, it has moved ^ of an inch 
but if either of these are moved to the center line then it is only 
moved ^ of this amount or ^ 

Figure 3 shows the usual application of the principle except that it 
is divided in four parts instead of ten. Here both the scales have 
four parts but on the lower scale the four parts just equal three parts 
of the upper scale. It is evident that if we move the lower scale so 
that o goes to i and 4 goes to 4 that it will be moved J the length 
of the distance o — 4 on the upper scale. If this distance was i inch, 
each division on the upper scale equals J inch and moving the lower 
scale so that the line i just matches the line next to o on the upper 
scale gives J of one of these divisions or -^ of an inch. 

316 



MEASURING THREE-FLUTED TOOLS 



317 



Figures 4 and 5 show the usual appHcation in which the lower or 
vernier scale is divided into 10 parts which equals 9 parts of the 
upper scale. The same division holds good, however, and when 
the lower scale is moved so that the first division of the vernier just 
matches the first line of the scale, it has been moved just one 
tenth of a division. In Fig. 4 the third lines match so that it has 
moved j^ and in Fig. 5, j"^ of a division. So if A B is one inch then 
each division is jq" of ^^ i^ch and each line of the vernier is yo of 
that or Y^o of an inch. 

To find the reading of any vernier, divide one division of the upper 
or large scale by the number of divisions in the small scale. So if 
we had a vernier with 16 divisions in each, the large scale being 
I inch long, then the movement of one division is j^ of jg or aie of 
an inch. 

READING THE MICROMETER 

The commercial micrometer consists of a frame, the anvil or fixed 
measuring point, the spindle which has a thread cut 40 to the inch 
on the portion inside the sleeve or barrel and the thimble which 
goes outside the sleeve and turns the spindle. One turn of the 





A — Frame 

B - Anvil ^ 

C - Spindle or Screw 

D - Sleeve or Barrel 

E- Thimble 



Fig. 6. — Micrometer 



screw moves the spindle 4V or .025 of an inch and the marks on the 
sleeve show the number of turns the screw is moved. Every fourth 
graduation is marked i, 2, 3, etc., representing tenths of an inch or 
as each mark is .025 the first four means .025 X 4 = -loo, the third 
means .025 X 4 X 3 = .300. 

The thimble has a beveled edge divided into 25 parts and num- 
bered o, 5, 10, 15, 20 and to o again. Each of these mean ^^5 of a 
turn or 2V of 4V = toVcT of an inch. To read, multiply the marks 
on the barrel by 25 and add the graduations on the edge of the 
thimble. In the cut there are 7 marks on the sleeve and 3 on the 
thimble so we say 7 X 25 = 175, plus 3 = 178 or .178. 

In shop practice it is common to read them without any multiply- 
ing by using mental addition. , Beginning at the largest number 



3i8 



CALIPERING AND FITTING 



shown on the sleeve and calling it hundreds and add 25 for each 
mark, we say in the case show 100 and 25, 50, 75 and then add the 
numbers shown on the thimble 3, making .178 in all. If it showed 
4 and one mark, with the thimble showing 8 marks, the reading 
would be 400 + 25 + 8 = 433 thousandths or .433. 

THE TEN-THOUSANDTH MICROMETER 

This adds a vernier to the micrometer sleeve or barrel as shown 
in Fig. 7, which is read the same as any vernier as has been ex- 
plained. First note the thousandths as in the ordinary micrometer 
and then look at the line on the sleeve which just matches a line on 




Thimble 



II II 



I nn II J 



43210 

Sleeve 



Thimble 



M I III I Mil 



098'654 32: 

Sleeve 



B 



Fig. 7. — Micrometer Graduations 

the thimble. If the two zero lines match two lines on the thimble, 
the measurement is in even thousandths as at B which reads .250. 
At C the seventh line matches a line on the thimble so the reading 
is .2507 inch. 



MEASURING THREE-FLUTED TOOLS WITH 
THE MICROMETER 

The sketch, Fig. 8 on page 319, shows a V-block or gage for 
measuring three-fluted drills, counterbores, etc. 

The angle being 60 degrees, the distances A, B, and C are equal. 
Consequently to determine the correct diameter of the piece to be 
measured, apply the gage as indicated in the sketch and deduct 
one third of the total measurement. 

The use of this gage has a decided advantage over the old way 
of soldering on a piece of metal opposite a tooth or boring out a ring 
to fit to. 

Using a standard 60-degree triangle for setting and a few different 
sizes of standard cylindrical plug gages for testing, the V-block 
may be easily and very accurately made. 



LIMITS FOR FITS 



319 












TJ 


I'lli! 













Fig. 8. — Measuring Three-Fluted Tools 



PRESS AND RUNNING FITS 

Parallel Press, Drive and Close Fits 

Table i, page 320, gives the practice of the C. W. Hunt Company, 
New York, for press, drive and close or hand J&ts for parallel shafts 
ranging between one and ten inches in diameter. In accordance with 
general practice, the holes for all parallel fits are made standard, except 
for unavoidable variation due to the wear of the reamer, the variation 
from standard diameter for the various kinds of fits being made in 
the shaft. This variation is, however, not positive, but is made 
between limits of accuracy or tolerance. Taking the case of a press 
fit on a two-inch shaft, for example, it will be seen that the hole — • 
that is, the reamer — is kept between the correct size and 0.002 inch 
below size, while the shaft must be between 0.002 and 0.003 i^ich 
over size. For a drive or hand fit the limits for the hole are the 
same as for a press fit, while the shaft in the former case must be 
between o.ooi and 0.002 large and in the latter between o.ooi and 
0.002 small. 

Parallel Running Fits 

Table 2, page 321, gives in the same way the allowances made by 
the same concern for parallel running fits of three grades of close- 
ness. The variations allowed in the holes are not materially dif- 
ferent from those of the preceding table, but the shafts are, of 
course, below instead of above the nominal size. 

In all cases the tables apply to steel shafts and cast-iron wheels or 
other members. In the right-hand columns of the tables the for- 
mulas from which the allowances are calculated are given, and from 
which the range of tables may be extended. 



320 



CALIPERING AND FITTING 







^s 


/^ 


■— N 














^~^ 












O M 








q 8 


O M 










§3 


Bq 








qq 








Jj 


+ + 


+ + 






• is 


+ 4- 


+ + 








B 

u 


XIT^ 


Tj-d 






"3 


-w 


'C-a 










lO >o 








vr> VO 








o 


M M 








o 


H H 


o o 








P>H 


11 

+ + 


+ + 






^ 


11 

+ 4- 


+ 4- 












xr> IT) 














II 




vovO 


n CO 


cs 


ro 


fo 


O M 


too 


tr>-± O Th 


-5 


o o 


o o 





O 


8. •; 




o o 





o o o 


•" 


q q 


q q 





q 


o q 


q q 





q q q 




+ + 


+ + 


1 


1 4- 


- 1 


+ 4 


+ + 


1 


1 + 1 
















lO to 








't vr> 


W ro 


es 


ro 


<^ 


CK O 


'^ VO 


ro -t O Tj- II 


g 


O O 


O O 





8 8 


O (3 


O M 


o o 


O 


q q q 


q q 


q q 





o -S 


o o 


q q 


O 


t 










o. 


• 










+ + 


+ + 


I 


1 -+ 


1 


44- 


4- + 


1 


1 4- I 






vo u-> 


















tr> -^ 


M C^ 




N Q 
O 


w 


^g^ 


rh VO 


CO rf O --t II 


.s 


8.8 


O O 





O d 


O O 


O 


8 88 


q q 


o 


q 


o -9 


o o 


O O 


O 


c^ 










00 


* 


' 




. . 




+ + 


+ + 


1 


1 4 


1 


4- + 


+ + 


1 


1 + 1 
















VO VO 








N m 


H n 




N 


C) 


^^ 


CO 'i- 


CO ^ O ^ II 


.5 


o o 


o o 





O 


o C 


o o 


o 


o o o 


q q 


q q 





q 


q .S 


q q 


q q 


o 


q q q 




+ + 


+ + 


1 


1 4 


1 


4 + 


+ + 


1 


1 + 1 




M M 


O M 




cj 


cq 


^^ 


CO rt 


N 


ro O CO 


,g 


o o 


o o 





O 


8 .s 


o o 


o 


o o o 


q q 


q q 


o 


q 


q q 


q q 


o 


q q q 


M 










VO 












+ + 


+ + 


1 


1 4 


1 


44- 


+ 4- 


1 


i + 1 










-v^ ^ 


s^ 


^^^ 




- 


-^ v^^ 


. 


""I^j 


^'^ 




<-(-i 


<+H 






"^ 


*t2 


«4-« -:s II 




c; 


c3 




rt 


o 


rt 


k3 




ca o 




x; 


43 




S > 


5 


-C 


^ 


CO W 




C/3 


CO 


CO >■ 


CO 


C/3 


S2 














; 2 
















(U 














• ^ 














































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II 



LIMITS FOR GAGES 



321 





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322 



CALIPERING AND FITTING 



Shrink Fits 

Table 3 gives the practice of the General Electric Company, 
Schenectady, New York, in regard to shrink fits, the same allowances 
also being made for press fits on heavy work such as couplings, etc. 



Table ■z. Allowances for Shrink Fits 



Dia. In. 


Allowance 


Dia. In. 


Allowance 


Dia. In. 


Allowance 


I 


.001 


20 


.008 


42 


.0143 


2 


.0015 


22 


.0088 


44 


.015 


3 


.0020 


24 


.0093 


46 


•0155 


4 


.0028 


26 


.0098 


48 


.016 


6 


•0035 


28 


.0105 


60 


.020 


8 


.0045 


30 


.oil 


72 


.024 


10 


.0053 


32 


.0115 


84 


.027 


12 


.0058 


34 


.012 


96 


.030 . 


14 


.0065 


36 


.0128 


108 


•033 


16 


.007 


38 


•0133 


120 


•0355 


18 


.0075 


40 


.0138 


132 
144 


.038 
.040 



LIMITS FOR GAGES 

The Newall Engineering Company, when developing their system 
of limit gages, investigated the practice of the leading English, 
Continental and American engineering concerns relative to allowances 
for different kinds of fits and prepared a table which is the average 
of all the data received, every point included being covered by the 
practice of some prominent establishment. The limits and allow- 
ances thus arrived at for shop gages are given in Table 4, which is 
self-explanatory. 



Table 



Limits and Allowances in Shop Gages for 
Different Kinds of Fits 



Nominal Diameters 



Over size . 
Under size 
Margin . . . 



,00025 
,00025 
000 !;o 



00050 
00025 
00075 



,00075 
,00025 
,00100 



001 00 

00050 
00150 



,00100 

,00050 
,00150 



OOIOO 

00050 



.00150 
,00050 
,00200 



Limits in Plug Gages for Standard Holes 
(Table Continued an Page 323) 



ALLOWANCES FOR FITS 



323 



Table 4 Continued. — Limits in Shop Gages 
Allowances — over Standard — for Force Fits 



Nominal Diameters 



Mean . . 
High . . 
Low. . . 
Margin 



00075 -ooiys 

ooioo .00200 
00050 .00150 
00050 .00050 



.00350 

.00400 
.00300 
.00100 



00525 

00600 

00450 



.00700 
.00800 
.00600 
001501.00200 



,00900 
,01000 
,00800 
,00200 



6" 



OIIOO 

,01200 
,01000 
,00200 



Allowances — over Standard — for Driving Fits 



Nominal Diameters §" 



Mean . . 
High . . 
Low . . 
Margin 



000375 
00050 
00025 
00025 



,000875 

OOIOO 

00075 

,00025 



.00125 

.00150 
.00100 
.00050 



00200 
00250 
00150 

OOIOO 



,00250 
.00300 
.00200 
.00100 



.00300 

.00350 

.00250 
.00100 



.00350 
.00400 
.00300 
.00100 



Allowances — Below'Standard — for Push or Keying Fits 



Nominal Diameters 



High . . 
Low . . . 

Margin 



,00025 
,00075 
,00050 



,00050 
,00100 
,00050 



OOIOO .00150 .00200 
,00150 .00200 .00250 
,00050 .00050 .00050 



,00200 
,00250 
,000501.00050 



Clearances for Running Fits 



Class of 
Gage 


Diameters 


r 


' 


2" 


3" 


4" 


5" 


6" 




Mean 


.00150 


.00200 


.00260 


.00320 


.00380 


.00440 


.00500 


X. 


1 High 


.00100 


.00125 


.00175 


.00200 


.00250 


.00300 


.00350 




Low 


.00200 


.00275 


.00350 


.00425 


.00500 


•00575 


.00650 




I Margin 


.00100 


.00150 


.00175 


.00225 


.00250 


.00275 


.00300 




Mean 


.00100 


.00150 


.00190 


.00230 


.00270 


.00310 


.00350 


Y. 


High 


.00075 


.00100 


.00125 


.00150 


.00200 


.00225 


.00250 




Low 


.00125 


.00200 


.00250 


.00300 


.00350 


.00400 


.00450 




I Margin 


.00050 


.00100 


.00125 


.00150 


.00150 


.00175 -00200 




("Mean 


.000625 


.00100 


.00120 


.00140 


.00160 


.00180 


.00200 


Z. 


High 


.00050 


.00075 


.00075 


.00100 


.00100 


.00125 


.00125 




Low 


.00075 


.00125 


.00150 


.00200 


.00225 


.00250 


.00275 




I Margin 


.00025 


.00050 


.00075 


.00100 


.00125 


.00125 


.00150 



Class X is suitable for engine and other work requiring easy fits. 
Class Y is suitable for high speeds and good average machine work. 
Class Z is suitable for fine tool work. 



324 CALIPERING AND FITTING 

Limits For Work Ground to Various Classes of Fits 

Table 5 gives the limits used by the Brown and Sharpe Manu- 
facturing Company in grinding work to various classes of fits required 
in machine manufacture. 

Table 5 — Grinding Limits for Cylindrical Pieces 
As Adopted by Brown and Sharpe Mfg. Co. 

RtTNNING FITS — ORDINARY SPEED 

To |-inch diameter, inc 0.00025 to 0.00075 Small 

To i-inch diameter, inc 0.00075 to 0.0015 Small 

To 2-inch diameter, inc 0.0015 to 0.0025 Small 

To 3|-inch diameter, inc 0.0025 to 0.0035 Small 

To 6-inch diameter, inc 0.0035 to 0.005 Small 

RUNNING FITS — HIGH SPEED, HEAVY PRESSURE AND ROCKER SHAFTS 

To ^-inch diameter, inc 0.0005 to o.ooi Small 

To i-inch diameter, inc o.ooi to 0.002 Small 

To 2-inch diameter, inc 0.002 to 0.003 Small 

To 3 ^-inch diameter, inc 0.003 to 0.0045 Small 

To 6-inch diameter, inc 0.0045 to 0.0065 Small 

SLIDING FITS 

To ^-inch diameter, inc 0.00025 to 0.0005 Small 

To I-inch diameter, inc 0.0005 to o.ooi Small 

To 2-inch diameter, inc o.ooi to 0.002 Small 

To 3^-inch diameter, inc 0.002 to 0.0035 Small 

To 6-inch diameter, inc 0.003 to 0.005 Small 

STANDARD FITS 

To ^-inch diameter, inc Standard to 0.00025 Small 

To I-inch diameter, inc Standard to 0.0005 Small 

To 2-inch diameter, inc Standard to o.ooi Small 

To 3|-inch diameter, inc Standard to 0.0015 Small 

To 6-inch diameter, inc Standard to 0.002 Small 

DRIVING FITS — FOR SUCH PIECES AS ARE REQUIRED TO BE READILY 
TAKEN APART 

To ^-inch diameter, inc Standard to 0.00025 Large 

To I-inch diameter, inc 0.00025 to 0.0005 Large 

To 2-inch diameter, inc 0.0005 to 0.00075 Large 

To 3^-inch diameter, inc 0.00075 to o.ooi Large 

To 6-inch diameter, inc o.ooi to 0.0015 Large 

DRIVING FITS 

To ^-inch diameter, inc 0.0005 to o.ooi Large 

To I-inch diameter, inc o.ooi to 0.002 Large 

To 2-inch diameter, inc 0.002 to 0.003 Large 

To 35-inch diameter, inc 0.003 to 0.004 Large 

To 6-inch diameter, inc 0.004 to 0.005 Large 



METRIC ALLOWANCES FOR FITS 325 

Table 5 Continued 



FORCING FITS 



To ^-inch diameter, inc 0.00075 to 0.0015 Large 

To i-inch diameter, inc 0.0015 to 0.0025 Large 

To 2-inch diameter, inc 0.0025 to 0.004 Large 

To 3|-inch diameter, inc 0.004 to 0.006 Large 

To 6-inch diameter, inc 0.006 to 0.009 Large 



SHRINKING FITS — FOR PIECES TO TAKE HARDENED SHELLS f INCH 
THICK AND LESS 

To |-inch diameter, inc 0.00025 to 0.0005 Large 

To i-inch diameter, inc 0.0005 to o.ooi Large 

To 2-inch diameter, inc o.ooi to 0.0015 Large 

To 3^-inch diameter, inc 0.0015 to 0.002 Large 

To 6-inch diameter, inc 0.002 to 0.003 Large 



SHRINKING FITS — FOR PIECES TO TAKE SHELLS, ETC., HAVING A 
THICKNESS OF MORE THAN f INCH 

To |-inch diameter, inc 0.0005 to o.ooi Large 

To I-inch diameter, inc o.ooi to 0.0025 Large 

To 2-inch diameter, inc. 0.0025 to 0.0035 Large 

To 3|-inch diameter, inc 0.0035 to 0.005 Large 

To 6-inch diameter, inc 0.005 to 0.007' Large 



GRINDING LIMITS FOR HOLES 

To ^-inch diameter, inc Standard to 0.0005 Large 

To I-inch diameter, inc Standard to 0.00075 Large 

To 2-inch diameter, inc Standard to o.ooi Large 

To 3|-inch diameter, inc Standard to 0.0015 Large 

To 6-inch diameter, inc Standard to 0.002 Large 

To 12-inch diameter, inc Standard to 0.0025 Large 



Metric Allowances For Fits of All Classes 

Table 6 covers allowances worked out by the Newall Engineering 
Company for use in connection with metric measurements; the 
allowances being given in decimals of a millimeter. 

The Newall system is based on a hole "basis," which means that 
all holes are produced as near the standard size as commercially 
possible and the allowances are made in the shaft or other fitting. 
The first part of the table shows the tolerances allowable in a standard 
hole for two grades of work which are designated by classes A and B. 
The remainder of the table covers fits of various classes. 



326 



CALIPERING AND FITTING 



Table 6 — The Newall Standard 

Tables of Allowances for Various Classes of Fits in Millimeters 

Tolerances in Standard Holes for Two Grades of Work 



Nominal Dia. 


Up to 15 1 16-25 


26-50 


51-75 


76-100 


IOI-I25 


126-150 


High limit 

Low limit 

Tolerance 


+ 0.007 

— 0.007 

0.014 


+ 0.013 

— 0.007 

0.020 


+ 0.019 

— 0.007 

0.026 


+ 0.026 

- 0.013 

0.039 


+ 0.026 

— 0.013 

0.039 


+ 0.026 

— 0.013 

0.039 


+ 0.039 

— 0.013 

0.052 


High limit 

Low limit 

Tolerance 


+ 0.013 

— 0.013 

0.026 


+ 0.019 

- 0.013 

0.032 


+ 0.026 

— 0.013 

0.039 


+ 0.032 

— 0.019 

0.052 


+ 0.039 

— O.OIQ 
0.058 


+ 0.045 

— 0.019 

0.064 


+0.051 

— 0.026 

0.077 







Force and Shrink Fits 


- 




Nominal Dia. 


Up to 15 


16-25 1 26-50 


51-75 


76-100 


101-125 


126-150 


High limit 

Low limit 

Tolerance ..... 


+ 0.026 

+ 0.013 

0.013 


+ 0.051 1 + 0.102 

+ 0.038 + 0.077 

0.013' 0.025 


+ 0.153 

+ 0.115 

0.038 


+ 0.204 

+ 0.152 

0.052 


+ 0.255 

+ 0.203 

0.052 


+ 0.306 

+ 0.254 

0.052 







Driving 


Fits 








Nominal Dia. 


Up to 15 


16-25 


26-50 


51-75 


76-100 


101-125 


126-150 


High limit 

Low limit 

Tolerance 


+ 0.013 

+ 0.007 

0.006 


+ 0.026 

+ 0.019 

0.007 


+ 0.039 

+ 0.026 

0.013 


+ 0.064 

+ 0.039 

0.025 


+ 0.077 

+ 0.051 

0.026 


+ 0.089 

+ 0.063 

0.02C 


+ 0.102 

+ 0.076 

0.026 



Push Fits 


— Go in Easy but wiU not Turn 




Nominal Dia. 


Up to 15 


16-25 

— 0.006 

— 0.019 
0.013 


26-50 


51-75 


76-100 


101-125 


126-150 


High limit 

Low limit 

Tolerance 


— 0.006 

— 0.019 
0.013 


— 0.006 

— 0.019 
0.013 


— 0.012 

— 0.026 
0.014 


— 0.012 

— 0.026 
0.014 


— 0.012 

— 0.026 
0.014 


— 0.012 

— 0.026 
0.014 



Running Fits for Engine and Similar Work 



Nominal Dia. 


Up to 15 


16-25 


26-50 SI-7S 


76-100 


101-125 


126-150 


High limit .... 

Low limit 

Tolerance 


- 0.025 

- 0.051 
0.026 


— 0.032 

— 0.070 
0.038 


— 0.045 — 0.051 

— 0.090 — 0.108 
0.045 0.057 


— 0.063 

— 0.127 
0.064 


— 0.076 

- 0.146 
0.070 


- 0.089 

- 0.16s 
* 0.076 



Running Fits for Good Average Machine Work 




Nominal Dia. 


Up to .15 16-25 ■ 26-50 


51-75 


76-100 


101-125 


126-150 


High Umit .... 

Low limit 

Tolerance 


1 

— 0.019 —0.0251 —0.032 

— 0.032' —0.051 —0.064 
0.013 1 o.o26| 0.032 


— 0.038 

— 0.076 
0.038 


— 0.051 

- 0.089 
0.038 


- 0.057 

— O.IOI 

0.044 


- 0.063 

— 0.II4 
0.051 





Running Fits for Fine Tool Work 






Nominal Dia. 


Up to 15 


16-25 


26-50 


51-75 


76-100 


101-125 


126-150 


High limit .... 

Low Mmit 

Tolerance 


— 0.012 

— 0.019 
0.007 


— 0.019 

— 0.032 
0.013 


— 0.019 

- 0.039 
0.020 


— 0.025 

— 0.051 
0.026 


— 0.025 

- 0.057 
0.032 


- 0.032 

— 0.064 
0.032 


- 0.032 

— 0.070 
0.038 



RUNNING FITS FOR POWER MACHINERY 327 

Press Fits For Wheel Hubs 

The practice of the Boston Elevated Railroad is to allow 8 tons 
per inch of diameter. An excess of 2 tons total pressure is allowed 
for cast iron, while the minimum pressure may be from 8 to 13 tons 
belov/ the normal according to diameter, as shown by the following 
table. These are for cast iron hubs \^ith the cone 5 inches in diam- 
eter — 7I inches long. For cast steel or wrought iron 20 per cent 
greater pressure is allowed. 



Diameter of 
Fit 


Minimum 
Pressure 


Maximum 
Pressure 


Variation 
AUowed 
in Tons 


2itO 2if 


12 


22 




3, to 3t\ 


16 


26 




3lto 3-f 
4 to 4tV 
4^ to 4]| 


20 

24 
28 


30 
34 
38 


10 


5 to 5tV 
5ito sH 


31 

35 


42 
46 


II 


6 to 61V 
6ito 6i| 


38 
42 


50 
54 


12 


7 to 7tV 
7lto 7it 


45 
49 


58 
62 


13 


8 to 81^ 
8^0 8i| 


52 
56 


66 
70 


14 


9 to 9 A 
9^ to gfl 

10 to lOxV 


59 
63 
67 


74 
78 
82 


15 



RUNNING FITS FOR POWER TRANSMISSION 
MACHINERY 

The Dodge Manufacturing Company has different standards 
for different classes of work for running fits. Their ordinary bear- 
ings vary from g^j inch for i inch to a little over -jV for 6 inches. 
Their clutch sleeves, which are babbitted, run very much closer, 
varying from 0.008 to about 0.0015 inch. Loose pulleys are some- 
times made as close as 0.003 inch on the smaller sizes. The com- 
pany has found that a good standard on loose pulleys is about gV 
on a 2^ inch hole and varying proportionately for diameters above 
and below that. This is very much freer than most people 
recommend, but it has been found that in the general trade there 
is more difficulty in having a little too tight a fit than there is in 
having the fit a little too loose. 



328 



CALIPERING AND FITTING 



MAKING ALLOWANCES WITH THE CALIPERS FOR 
RUNNING, SHRINK, AND PRESS FITS 

One of the familiar devices of the machinist consists in giving 
the inside calipers a certain amount of side play, when it is desir- 
able to obtain a measure minutely less than the full diameter of the 
hole, as in making a loose or running fit, or a sliding fit as of a 
plunger in a cylinder. Thus in Fig, g, A is the diameter of the bore, B 
the caliper setting and C the side play permitted the caliper in the hole. 

In the table below is given a list of the reduced dimensions for 
different amounts of side play of the calipers in a 12-inch hole. 
From this, the dimensions may be obtained for holes of other diam- 
eters by division. Where in the table the side play is 2 inches, if 
we divide the items by 4 we have the side play and the reduced 
dimension for a 3-inch hole, or 0.5 inch and 2.9894 inches respectively. 




Fig. 9. — Side Play of the Calipers 

Table of Reduced Diameters Indicated by Inside Calipers 
FOR Different Amounts of Side Play in a i 2-inch Hole 
Side play 

0.1 11.9999 

0.2 II. 9991 

0.4 11.9983 

0.6 11.9962 

0.8 11.9933 

i.o 11.9895 

1.2 11.9849 

1.4 11-9795 

1.6 11.9730 

1.8 11.9660 

2.0 11-9579 

2.2 .11.9490 

2.4 II-939I 

2.5 11.9339 

3.0 r r • • • 11-904'^ 



CALIPER SIDE PLAY 



329 



Axial Inclination of the Calipers in Measuring for Shrink or 
Press Fits 

In the case worked out on page 328, it was desired to produce a hole 
slightly larger than the piece to go into it, or a piece slightly smaller 
than the hole. In operations where a hole is wanted somewhat smaller 
than the piece to be shrunk or pressed into ft, a similar plan of meas- 
uring can be employed, and a table giving the tightness can be 
computed. The sketch, Fig. 10, will serve to make the meaning clear. 
The distance A is the diameter of a hole and line a is the length of 
a gage the exact size of the piece to be pressed or shrunk into the 
hole. The distance b is the amount the gage lacks of assuming a 
position square or at a right angle to the axis of the hole. 

It is an easy matter to make a table as suggested. It is only 
necessary to find the different lengths for the hypotenuse a for the 
right-angle triangle of which A is the constant base and b the per- 
pendicular, taking b at different lengths from | inch to 2 inches. 
Assuming the diameter to be 12 inches, then the lengths indicated 
for different inclinations in the direction of the axis will be as given 
in the following table. 




Fig. 10. — Inclination of the Calipers for Press Fits 



Table for Axial Inclination of Calipers in Allowing for 
Shrink or Force Fits in a i 2-inch Hole 

Inclination of 

calipers ^ 

i inch 12.00065 

i inch 1 2.00260 

f inch 12.00580 

I inch 1 2.01040 

t inch 12.01626 

f inch 12.02340 

I inch 12.03180 

I inch 12.04159 

ij inches 12.06490 

I J inches 12.09338 

if inches 12.12689 

2 inches 12.16550 



330 CALIPERING AND FITTING 

Side Play of Calipers in Boring Holes Larger than a Piece 
of Known Diameter 

The following is an approximate rule for obtaining the variation 
in the size of a hole corresponding to a given amount of side play 
in the calipers. The rule has the merit of extreme simplicity and 
can be applied equally well to all diameters except the very smallest. 
In most cases the calculation is so simple that it can be done men- 
tally without having recourse to pencil or paper. 

The Calculation 

Let A in Fig. 1 1 = side play of calipers or end measuring rod m 

sixteenths of an inch. 

B = dimensions to which calipers are set, or length of measuring 

rod in inches. 

C = difference between diameter of hole and length of B in 

thousandths of an inch. 

A^ 
Then C = —x, within a very small limit. 

2/> 




Fig. II. — Caliper Side Play 



Example: A standard end measuring rod, 5^ inches long, has 
I inch of side play in a hole. What is the size of the hole ? In this 
case A = 6 and 5 = 5J. Apply the above formula: 

C = = — = 3.27 thousandths of an inch, or 0.00327 inch. 

II II 

The diameter of the hole, therefore, is 5I + 0.00327 or 5.50327. 

The method ^yill be found to be correct within a limit of about 
0.0002 inch if the amount of side play is not more than one eighth 
of the diameter of the hole for holes up to 6 inches diameter; within 
0.0005 iJ^ch for holes from 6 inches up to 12 inches; and within o.ooi 
for holes from 12 inches up to 24 inches. 



DIMENSIONS OF KEYS AND KEY-SEATS 331 

Allowing for Running and Driving Fits 

This rule has been found to be useful for boring holes of large 
diameters in which allowances have to be made for running or 
driving fits, as only a single measuring rod for each nominal size is 
required. The rods should be of standard length, or a known 
amount less than standard, the allowances being obtained by varying 
the amount of side play when boring. The rule is also capable of 
determining limits, as the maximum and minimum amount of side 
play allowable can be specified. The measuring rods should be 
tapered at each end and the points slightly rounded. For accurate 
work, the body of the rod should be encased in some non-conducting 
material to nullify the effect of the heat of the hand. 

In comparing this method with that described on page 330, it 
should be remembered that the conditions are reversed — that is 
to say, the first method is for setting calipers to a given dimension 
smaller than a hole of known diameter, whereas the method now 
described is for boring a hole a given amount larger than a gage of 
known length. 

In measuring the side play it is sufficient to take it to the nearest 
sixteenth of an inch, and if anything like accuracy is required it 
should be measured not guessed at. 



DIMENSIONS OF KEYS AND KEY-SEATS 

The following rules and table on page 332, as prepared by Baker 
Bros., Toledo, Ohio, give dimension of keys and key-seats. 

The width of the key should equal one fourth the diameter of the 
shaft. 

The thickness of the key should equal one sixth the diameter of 
the shaft. 

The depth in the hub for a straight key-seat should be one half 
the thickness of the key. 

The depth in the hub at the large end, for a taper key-seat, should 
be three fifths the thickness of the key. 

The taper for all key-seats should be -f-^ inch in i foot of length. 

The depth to be cut in the hub for taper key-seats, at the large 
end, is greater than those cut straight, for the reason that unless 
this is done the depth in the hub at the small end will not be sufficient, 
especially in long key-seats. 

The depths of key-seats in the table are given in thousandths of 
an inch and measured from the edge of the key-seat, and not from 
the center. In this manner the exact depth of key-seat can be 
measured at any time after it is cut. 

For extra long key-seats the depth cut in the hub may be slightly 
increased, but for the average work the table will be found correct. 



2>Z2 



CALIPERING AND FITTING 



Dimensions of Keys and Key-Seats. (Baker Bros.) 



Size of 
Hole 


Decimal 


Preferred 


Nearest 


Preferred 


Nearest 


Depth to -n 
be Cut in Ji 
Hub for r 
Straight *°' 
Key 


epth at 
rge End 


Equiv- 


Width of 


Size of 


Thickness 


Fractional 


alent 


Key-Seat 


Cutter 


of Key 


Thickness 


Taper 

Key 


I 


I. 


.25 


i 


.166 


t\ 


.093 


112 


itV 


1.062 


.265 


i 


.177 


♦ 


•093 


112 


li 


1. 125 


.281 


i 


.187 




.093 


112 


lA 


1. 187 


.296 


T^ 


.198 


sV 


.109 


131 


li 


1.25 


.312 


^? 


.208 


J2 


.109 


131 


H-" 


1-312 


.328 


♦ 


.219 


^2 


.109 


131 


^% 


1-375 


•343 


t 


.229 


i 


.125 


15 


ii^ 


1-437 


•359 


1 


•239 


i 


-125 


15 


^\ 


1-5 


•375 


1 


•25 


i 


.125 


15 


lA 


1.562 


•39 


f 


.26 


i 


•125 


15 


if 


1.625 


.406 


tV 


.271 


z% 


.141 


168 


iH 


1.687 


.421 


t\ 


.281 


J% 


.141 


.168 


if 


1-75 


•437 


tV 


.292 


j\ 


.141 


168 


iH 


1.812 


-453 


tV 


.302 


A 


.141 


168 


il 


1-875 


.468 


h 


.312 


-i 


.171 


206 


lit 


1-937 


.484 


h 


•323 


;f 


.171 


206 


2 


2. 


•5 


h 


'333 




.171 


206 


2tV 


2.062 


•515 


i 


.344 


V- 


.171 


206 


2i 


2.125 


•531 


h 


-354 


i 


.171 


206 


2A 


2.187 


•547 


h 


-364 


^2 


.171 


206 


2i 


2.25 


-563 


h 


-375 


H 


•171 


206 


2^ 


2.312 


.578 


h 


-385 


M 


.171 


206 


2f 


2.375 


.593 


f 


•396 


tV 


.218 


262 


2tV 


2.437 


.609 




.406 


tV 


.218 


262 


2^ 


2.5 


-625 


1 


.416 


tV 


.218 


262 


2A 


2.562 


.641 


1 . 


•427 


tV 


.218 


262 


2f 


2.625 


.656 


•I 


•437 


t\ 


.218 


262 


2H 


2.687 


.672 


1 


-448 


t\ 


.218 


262 


2i 


2-75 


.687 


1 


-458 


IV 


.2l8 


262 


2H 


2.812 


•703 


f 


.469 


tV 


.218 


262 


2| 


2.875 


.719 


f . 


-479 


i 


•25 


3 


2H 


2-937 


•734 


f 


.49 


h 


•25 


3 


3 


3- 


•75 


f 


•5 


h 


•25 


3 


3i 


3-125 


.781 


1 


.521 


h 


•25 


3 


3A 


3-187 


-797 


1 


-531 


h 


•25 


3 


3i 


3-25 


.812 


f 


.542 


h 


•25 


3 


^\ 


3-375 


-844 


i 


.562 


1 


•312 


375 


3tV 


3-437 


•859 


1 


-573 


1 


.312 


375 


3i 


3-5 


•875 


7 
8 


•583 


f 


.312 


375 


3f, 


3-625 


.906 


f 


.604 


1 


•312 


375 


3H 


3.687 


.923 




.614 




.312 


375 


3f 


3-75 


.937 


1 


.625 


f 


•312 


375 


4. 


3-875 


.969 


I 


.646 


li 


-343 


412 


3il 


3-937 


.984 


I 


.656 


li 


-343 


412 


4 


4. 


I. 


I 


.666 


IF 


-343 


412 



STRAIGHT KEYS 



333 



DIMENSIONS OF STRAIGHT KEYS 

Another system of keys used by a good many manufacturers is 
given in the table following, the sizes of shafts ranging by sixteenths 
from ■f'-Q inch to 4 inches and by eighths from 4 to 6 inches. The 
keys are square until the i| inch shaft is reached, when the thickness 
of the key becomes yV less than the width. With the 4^ size the 
thickness of the key becomes | inch less than the width and this 
difference is constant up to the 5J shaft when the width exceeds the 
thickness by -^ inch, this difference in the two dimensions continu- 
ing throughout the remainder of the table. 



Dimensions of Straight Keys 





>> 


<M 


•a 


>. 


t« 


^ 


>. 


^ 




>t 


^ 


JS 


t^ 





c3 


^ 







t^ 





3 


OJ 





C/2 




vi 


C/3 


«*-4 


m 


CO 


«*H 


^ 


w 


<4-l 


CO 




"o 


^ 


«*-! 





al 


tM 












u 




•3 

•T3 


ll 




c5 


rSi 
■5 





i 


,5 


Is- 




.•2 


ll 


5 


'^ 


H 


,5 


'^ 


H 


Q 


'^ 


H 


Q 


^ 


H 









li 


A 


A 


2^ 


i 


tV 


3f 


1 


11 


tV 






IT^ 


1^ 


A 


2t^^ 


A 


i 


3il 


f 


-i 


i 






If 


A 


t\ 


2f 


T% 


J 


3l 


if 


4 


A 






itV 


^^ 


T% 


2ii 


A 


i 


3il 


if 


f 


i 






I^ 


A 


t\ 


2| 


¥ 


h 


4 


if 


f 


1% 


3% 


1% 


lA 






2H 




i 


4i 


if 


1 


t 


/. 


j\ 


If 


f 


1 


2| 


t\ 


h 


4i 




i 


i^ 


i 


i 


lii 


1 


f 


2i| 


1 


A 


4l 


1 


f 


h 


t 


i 


if 


1 




3 


f 


T% 


4^ 


it 


if 


T% 


i 


i 


lit 


f 


1 


3t6 


1 


1% 


4f 


if 


il 


f 


t\ 


T% 


I5 


T^e 


1 


3* 


f 


1% 


4l 


I 


f 


ii 


j\ 


l\ 


lit 


tV 


■g 


3tV 


f 


A 


5 


I 




f 


♦ 


t\ 


2 


tV 




3i 




f 


5i 


itV 


1 


if 


A 


T^6 


2tV 


tV 


1 


3t\ 


ie 




5i 


ItV 


7 

8 


1 


T% 


fV 


2i 


tV 


f 


31 


16" 


1 


5i 


ItV 


7 
8 


H 






2t\ 


i 


1^ 


3tV 


ii 


1 


si 


li 


T* 


I 






2i 


h 


1^ 


3i 


i| 


1 


5f 


li 


-f 


ixV 






2tV 


h. 


A 


3tf 




H 


5f 


ll 


H 


li 






2| 


h 


tV 


3f 


f 


ii 


5l 


it\ 


I 


it\ 






2tV 


' 


re 


3H 


^ 


ii 


6 


lA 


I 



SQUARE FEATHER KEYS AND STRAIGHT KEY SIZES 

The tables on page 334 give the sizes of square feather keys and 
regular straight keys in accordance with the practice of Jones & 
Laughlin, Pittsburg, For taper keys, this concern and many others 
use a |-inch per foot taper. 



334 CALIPERING AND FITTING 

Square Feather Key Sizes. (Jones & Laughlin) 



Dia. of Shaft 


Size of Key 


Dia. of Shaft 


Size of Key 


I to l| 


i X i 


3T6 to 3I 


ilx H 


lA toil 


AX A 


3tV to 3f 


1 X i 


IjV to if 


1 X f 


3H to 3f 


iix H 


iji to i| 


A X j\ 


3-1 to 4 J 


I X I 


I-f to 2j 


i X ^ 


4t6 to 4| 


itV X itV 


23% to 2| 


AX A 


4t6 to 4f 


ij Xii 


2i^ to 2f 


1 X f 


4H to 5i 


li X li 


2H to 2| 


iixH 


5t6 to 5i 


if X if 


2lt to 3i 


f X f 


5ll to 6i 


ih Xih 



Straight Key Sizes. 


(Jones & Laughlin) 


Dia. of Shaft 


Size of Key 


Dia. of Shaft 


Size of Key 


I to li 


i XA 


3Ato3l 


Hx il 


iT^toif 


A X 3V 


3tV to 3f 


i X if 


itV to If 


f X i 


SH to 3l 


iix t 


iH to i| 


A X j% 


3Tt to 4i 


I X H 


lit to 2i 


i XH 


4A to 4f 


lAx ii 


2fV to 2| 


AX t 


4tV to 4l 


li X f 


2yV to 2f 


f x^f 


4H to 5i 


li X tl 


2H to 2| 


11 X -f 


5A to 5| 


If X II 


2if to 3i 


1 X ^ 


5H to 6i 


i| X I 





The Earth Key 




/ ,K 


^ 


\ 



-w- 



No. of Key 


w 


w 


D 


I 


1 


.132 


tIs 


2 


A 


.165 


■ii 


3 


A 


.199 


* 


4 


1 


.264 


6\ 


5 


A 


.329 


A 



PRATT AND WHITNEY KEY SYSTEM 



335 







Keys made with 
\ Bound Ends and 


( 




^ -m KejTfays Cut in 
/. _y - Bpline MUler 


_JIIIII' 




:lii|i|-r. A ^ -) 1 


f 


-I^ 


3]^-?(^ 



The Length "L" may vary from the table given, but must at least 
be equal to (2 X W). The maximum length of slot which can be 
cut in the Sphne Milling machine in one cut; is (4" + W). Note 
that the Width (W) is in all cases equal to the depth (D). 

Pratt & Whitney Key System 



Key 
No. 


L 


w 


H 


D 


No. 


L 


W 


H 


D 


I 




tV 


A 


tV 


22 




i 


1 


i 


2 


1 


A 


^^T 


A 


23 


If 


A 


if 


T^6 


3 




i 


t\ 


i 


F 




f 


T^6 


1 


4 




A 


6^1 


A 


24 




1 


1 


i 


5 


1 


i 


j\ 


i 


25 


li 


1^6 


if 


t\ 


6 




/^ 


if 


A 


G 






T% 


f 


7 




i 


T^. 


i 


51 




1 
4 


f 


1 

4 


8 


i 


/^ 


if 


A 


52 


If 


fV 


if 


t\ 


9 




t\ 


/. 


xV 


S3 




f 


T^^ 


1 


10 




/2 


if 


A 


26 




t\ ' 


A 


t\ 


II 


1 


A 


¥2 


t\ 


27 


2 


i 


f 


i 


12 


« 


^. 


fi 


A 


28 




T^6 


if 


A 


A 




1 
4 


1 


i 


29 




3 

8 


T^^ 


t 


13 




tV 


3^2 


A 


54 




i 


f 


1 


14 


I 


aV 


U 


A 


55 


2i 


1^ 


if 


A 


15 


i 


t 


1 

4 


56 


f 




1^ 


B 




A 


if 


A 


57 




tV 


fi 


A 


16 




¥ 


3\ 


A 


58 




A 


if 


t\ 


17 


li 


¥'2 


2 1 

64 


A 


59 


ol 


f 


T^,I 


f 


18 


i 


3 

8 


i 


60 


22 


iV 


li 


tV 


C 




t\ 


if 


T^e 


61 




1 
2 


3 

4 


i 


19 




A 


j\ 


T^,I 


30 




f 


t\ 


1 


20 




s\ 


u 


A 


31 




tV 


¥ 


j^ 


21 


li 


1 
4 


1 


I 


32 


3 


i 




1 


D 




A 


if 


A 


33 




A 


fa 


A 


E 




1 


T% 


f 


34 




f 


il 


f 



336 



CALIPERING AND FITTING 



/ 



Shaft 




Whitney Keys and Cutters. Nos. i to 26 
(Woodrufif's Patent) 



No. of 
Key 
and 

Cutter 


Dia. of 
Cutter 


Thick- 
ness of 
Key 
and 
Cutter 


Length 
Key 


Key 
Cut 
Below 
Cen- 
ter 


No. of 
Key 
and 

Cutter 


Dia. 
of 

Cut- 
ter 


Thick- 
ness of 
Key 
and 
Cutter 


Length 
Key 


Key 
Cut 
Below 
Cen- 
ter 




A 


B 


C 


D 




A 


B 


C 


D 


I 


i 


tV 


1 


^^ 


16 


li 


fV 


li 


/t 


2 


h 


3\ 


i 




17 


li 


^'^ 


li 


«^T 


3 


h 


i 


i 


"^4 


18 


li 


1 

4 


li 


6^? 


4 


^ 


j\ 


& 


tV 


c 


i^ 


1^ 


i^ 


^ 


5 




i 


t 


tV 


19 


li 


fk 


li 


^4 


6 


f 


i'2 


* 


tV 


20 


li 


3V 


li 


6^T 


7 


f 


i 




1^« 


21 


li 


i 


li 


K^T 


8 


1 


^', 


f 


tV 


D 


li 


A 


li 


<fV 


9 


-i 


A 


f 


tV 


E 


li 


i 


li 


If-T 


10 


'i 


aV 


i 


tV 


22 


i^ 


i 


it 


3^*^ 


II 


'i 


t\ 


i 


T^. 


23 


l| 


T^. 


It 


^\ 


12 


8 


3% 


^ 


1^6 


F 


l^ 




it 


Ji 


A 


I 


i 


^ 


tV 


24 


li 


1 


i^ 


/? 


13 


I 


^ 


I 




25 


l^ 


1^« 


i^ 


^V 


14 


I 


^ 


I 


tV 


G 


li 


f 


i^ 


^'l 


15 


I 


i 


I 


T6 












B 


I 


t'V 


I 


" 













i 

.L. 


= 



Cutter 



w C- 



Shaft 



V Ie "^ 



n 

Note : Refer to table at top of page 337 for values of dimension E. 



PROPORTIONS OF KEY HEADS 



337 





Whitney Keys and Cutters. Nos. 26 to 


36 






fe 




>» 

^ 


1 




1 


fc 


5- 


>. 


1 




^ 




•^fe 


'o 


m 


^ 




p 


oiJ 


t^ 


m 


^ 


6^ 







.5 


^1 

5TU 




^1 


u 

.52 


go 




'So 

3 




15 1^ 


2 


Q 


H 


^ 


't^ 


2 


Q 


H 


i4 


E 




A 


B 


C 


D 


E 




A 


B 


c 


D 


E 


26 


2i 


t\ 


ift 


*l 


j\ 


30 


3i 


f 


2i 


if 


t\ 


27 


2i 


i 


III 


tf 


3\ 


31 


3* 


tV 


2^ 


H 


t\- 


28 

2Q 


2i 
2^ 


f 


ifl 
Iff 




A 


32 


3i 
3h 


i 


2| 

2| 


11 
if 


t\ 


R 


2f 


1 


2tV 


1 


i 


S3 


T6 


16 


S 


2f 


t\ 


2t\ 


1 


* 


34 


Si 


f 


2| 


if 


tV 


T 


2f 


T6 


2X> 


1 


i 


3'> 


si 


H 


2| 


H 


t\ 


U 
V 


2* 
2| 


2X^6 


1 


i 


36 


Si 


1 


2i 


if 


1^6 



Proportions of Key Heads 
(standard gage steel CO.) 



'rB-^ 



A 


B 


c 


D 


A 


B 


c 


D 


i 


i 


i 


3^ 


If 


If 


2i 


i^ 


a^ 


tV 


T^^ 


^\ 


lU 


I-i 


2| 


iH 


i 


i 


it 


l^i 


if 




3 


2 


T^ 


A 


1^6 




lit 


iH 


3i 


2tV 


1 


f 


ii 


-f 


ll 


ll 


3l 


2^ 


1^6 


tV 


f 


-| 


III 


iH 


3l 


2t^^ 


^ 


i 


^ 


-| 


2 


2 


3f 


2i 


l\ 


A 




^ 


2tV 


2tV 


Si 


2tV 


f 


1 


ll 


-f 


2i 


2| 


4 


2i 


ii 


ii 


IT^W 


-| 


2^ 


2A 


4i 


2t% 


f 


f 


jl 


f 


2i 


2i 


4i 


2| 


H 


+* 


IfV 


H 


2t^ 


2t% 


4f 


2H 


1 


• i 


I^ 


I 


2f 


2f 


4i 


2f 


if 


i^ 


if 


itV 


2t'w 


2tV 


4l 


2H 


I 


I 


I-- 


li 


2h 


2h 


4f 


2^ 


i^ 


itV 


iH 


ifV 


2tV 


2A 


4l 


2H 


li 


li 




ifV 


2f 


2f 


5 


3 


IT^ 


it\ 


lit 


if 


2H 


2H 


5 


3T6 


l| 


li 


2 


IV^ 


2f 


2| 


5i 


3^ 


lA 


rtv 


2i 


I^ 


2H 


2H 


5i 


3T6 


If 


If 


2i 


II^ 


2| 


2i 


Si 


3i 


ii^ 


It^ 


2^ 


If 


2H 


2H 


5i 


3i^ 


i| 


I^ 


2^ 


Ij 


3 


3 


5l 


3l 


ii^ 


IT^ 


2t 


iH 











338 CALIPERING AND FITTING 

Table for Finding Total Keyway Depth 



—La 




In the column marked "Size of 
Shaft" find the number representing 
the size; then to the right find the 
column representing the keyway to be 
cut and the decimal there is the dis- 
tance A, which added to the depth of 
the keyway will give the total depth 
from the point where the cutter first 
begins to cut. 



Size 

of 

Shaft 


i 


fs 


1 


/s 


i 


Keyway 


Keyway 


Keyway 


Keyway 


Keyway 


^ 


0.0325 











^ 


0.0289 











^ 


0.0254 


0.0413 









H 


0.0236 


0.0379 








f 


0.022 


0.0346 


O.0511 







H 


0.0198 


0.0314 


0.0465 









0.0177 
0.0164 


0.0283 
0.0264 


0.042 
0.0392 


0.0583 
0.0544 






I 


0.0152 


0.0246 


0.0365 


0.0506 


0.067 


ItV 


0.0143 


0.0228 


0.0342 


0.0476 


0.0625 


I* 


0.0136 


0.021 


0.0319 


0.0446 


0.0581 


IT^.- 


0.0131 


0.0204 


0.0304 


0.0421 


0.0551 


li 


0.0127 


0.0198 


0.029 


0.0397 


0.0522 


ifV 


0.0123 


0.0191 


0.0279 


0.038 


0.0499 


If 


0.012 


0.0185 


0.0268 


0.0364 


0.0477 


IT^ 


0.0114 


0.0174 


0.0254 


0.0346 


0.0453 


I^ 


O.OII 


0.0164 


0.024 


0.0328 


0.0429 


1T% 


0.0107 


0.0158 


0.0231 


0.0309 


0.0412 


I* 


0.0105 


0-0153 


0.0221 


0.0291 


0.0395 


iH 


0.0102 


0.0147 


0.0214 


0.0282 


0.0383 


If 


0.0099 


0.0142 


0.0207 


0.0274 


0.0371 


iH 


0.0095 


0.0136 


0.0198 


0.0265 


0.0355 


li 


0.0093 


0.013 


0.019 


0.0257 


0.0339 


l|^ 


0.009 


0.0127 


0.0184 


0.025 


0.0328 


2 


0.0088 


0.0124 


0.0179 


0.0243 


0.0317 


2tV 


0.0083 


0.0117 


0.0173 


0.0236 


0.0308 


2i 


0.0078 


O.OII I 


0.0168 


0.0229 


0.0299 


2A 


0.0073 


0.0109 


0.0163 


0.0222 


0.0291 


2i 


0.007 


0.0107 


0.0159 


0.0216 


0.0282 



FINDING TOTAL KEYWAY DEPTH 
Table for Finding Total Keyway Depth 



339 



In the column marked "Size of 
Shaft" find the number representing 
the size; then to the right find the 
column representing the keyway to be 
cut and the decimal there is the dis- 
tance A, which added to the depth of 
the keyway will give the total depth 
from the point where the cutter first 
begins to cut. 



-_.LA 




Size 


i 


i-k 


f 


i'b 


i 


of 
Shaft 












Keyway 


Keyway 


Keyway 


Keyway 


Keyway 


2A 


0.0068 


0.0104 


0.0155 


0.0209 


0.0274 


2j 


0.0066 


0.0102 


0.0152 


0.0202 


0.0267 


2tV 


0.0064 


O.OI 


0.0149 


0.0198 


0.026 


2h 


0.0063 


0.0098 


0.0146 


0.0194 


0.0253 


2j\ 


0.0061 


0.0094 


0.0142 


0.0189 


0.0247 


2f 


0.006 


0.009 


0.0139 


0.0185 


0.0242 


2H 


0.0059 


0.0089 


0.0136 


0.018 


0.0236 


2f 


0.0058 


0.0088 


0.0133 


0.0176 


0.023 


2H 


0.0057 


0.0086 


0.0129 


0.0172 


0.0226 


2| 


0.0056 


0.0084 


0.0126 


0.0168 


0.022 


2M 


0.0054 


0.0083 


0.0122 


0.0164 


0.0216 


3 


0.0053 


0.0081 


0.0119 


0.0161 


0.0211 


3t6 


0.0052 


0.008 


0.0116 


0.0158 


0.0207 


3i 


0.0051 


0.0078 


0.0114 


0.0155 


0.0202 


3^ 


0.005 


0.0076 


O.OI I 2 


0.0152 


0.0198 


3i 


0.0049 


0.0075 


O.OII 


0.0149 


0.0194 


3A 


0.0048 


0.0074 


0.0108 


0.0146 


O.0191 


^K 


0.0047 


0.0072 


0.0106 


0.0143 


0.0187 


Sfe 


0.0046 


0.0071 


0.0104 


0.014 


0.0184 


^K 


0.0045 


0.007 


0.0102 


0.0138 


0.018 


3t6 


0.0044 


0.0069 


O.OIOI 


0.0135 


0.0188 


4. 


0.0043 


0.0067 


O.OI 


0.0133 


0.0174 


3H 


0.0042 


0.0066 


0.0099 


0.0131 


0.0171 


3l 


0.0042 


0.0065 


0.0098 


0.0128 


0.0168 


3H 


0.0041 


0.0064 


0.0097 


0.0126 


0.0166 


^l 


0.0041 


0.0063 


0.0096 


0.0124 


0.0163 


3il 


0.0041 


0.0062 


0.0095 


0.0123 


0.0161 


4 


0.004 


0.0061 


0.0094 


O.OI2I 


0.016 



340 



CALIPERING AND FITTING 



Tapers for Keys, etc., from -^^ to i inch per Foot. Amount 
OF Taper for Lengths Varying by J inch 



1 


Length 


1 


I 


li 


2 


2i 


3 


3i 


4 


4i 


S 


5i 


6 


tV 


.oo';2 


.0078 


.0104 


.0130 


.0156 


.0182 


.0208 


.0234 


.0260 


.0286 


.0312 


* 


.0104 


.0156 


.0208 


.0260 


.0312 


.0364 


.0416 


.0468 


.0520 


.0572 


.0625 


t\ 


.0156 


.0234 


.0312 


.0390 


.0468 


.0546 


.0625 


.0703 


.0781 


.0859 


•0937 


i 


.0208 


.0312 


.0416 


.0520 


.0625 


.0729 


•0833 


•0937 


.1041 


.1145 


.1250 


T^^ 


.0260 


.0390 


.0520 


.0650 


.0781 


.0911 


.1041 


.1171 


.1302 


.1432 


.1562 


1 


.0312 


.0468 


.0625 


.0780 


•0937 


.1092 


.1250 


.1406 


.1562 


.1718 


•i«75 


T^ 


.0364 


.0546 


.0729 


.0911 


•1093 


•1275 


.i45« 


.1640 


.1822 


,2004 


.2187 


h 


,0416 


.0624 


•0833 


.1041 


.1250 


•1457 


.1666 


.1874 


.2083 


.2291 


.2500 


^ 


.0468 


.0702 


•0937 


.1171 


.1406 


.1641 


•i«75 


.2109 


•2343 


•2577 


.2812 


f 


.0520 


.0780 


.1041 


.1301 


.1562 


.1823 


.2083 


•2343 


.2604 


.2864 


•3125 


ii 


.0572 


.0858 


•I 145 


•143 I 


.1718 


.2004 


.2291 


•2577 


.2864 


•3150 


•3437 


f 


.0625 


.0938 


.1250 


•1.03 


•1875 


.2188 


•2500 


•2813 


•3125 


•343« 


•3750 


H 


.0677 


.1016 


•1354 


.1693 


.2031 


.2370 


.2708 


•3047 


•33«5 


•3724 


.4062 


i 


.0729 


.1094 


.1458 


.1823 


.2187 


•2552 


.2916 


•3281 


■3O45 


.4010 


•4375 


i* 


.0781 


.1172 


.1562 


•1953 


•2343 


•2734 


•3125 


•3515 


.390b 


.4295 


.4687 


I 


.0833 


.1250 


.1666 


.2083 


.2500 


.2916 


■3333 


.3749 


.4166 


.45^2 


.5000 



1 

u 

1 


Length 


6i 


7 


7-^ 


8 


8i 


9 


9h 


10 


loi 


II 


iii 


tV 


•0338 


.0364 


.0390 


.0416 


.0442 


.0468 


.0494 


.0520 


.0546 


.0572 


.0598 


i 


.0677 


.0729 


.0781 


•0833 


.088 s 


•0937 


.0989 


.1041 


.1093 


.1145 


.1197 


A 


.1015 


•1093 


.1171 


.1250 


.1328 


.1406 


.1484 


.1562 


.1640 


.1718 


.1796 


i 


■1354 


.1458 


.1562 


.1666 


.1770 


•1875 


.1979 


.2083 


.2187 


.2291 


•2395 


1^ 


.1692 


.1822 


•1952 


• 2083 


•2213 


•2343 


•2473 


.2604 


•2734 


.2864 


.2994 


^ 


.2031 


.2187 


•2343 


.2500 


.2656 


.2812 


.2968 


•3125 


•3281 


•3437 


•3593 


tV 


.2369 


•2552 


•2734 


.2916 


.3098 


•3281 


•3463 


•3645 


•3827 


.4010 


.4192 


i 


.2708 


.2916 


•3124 


.3333 


•3541 


•3750 


.3958 


.4166 


•4374 


•4583 


•4791 


^ 


.3046 


.3281 


•3515 


•3750 


•3984 


.4218 


•4452 


.4687 


.4921 


•515^ 


•5390 


* 


•3385 


•3645 


•3905 


.4166 


.4426 


.4687 


•4947 


.5208 


•5468 


•5729 


.5989 


H 


•3723 


.4010 


.4296 


•4583 


.4869 


•5156 


•5442 


•5729 


.6015 


.6302 


.6588 


i 


.4063 


•4375 


.4688 


.5000 


•5313 


•5625 


•5938 


.6250 


.6563 


.6875 


.7188 


+* 


.4401 


•4739 


.5078 


•5416 


•5755 


.6093 


.6432 


.6770 


.7109 


•7447 


.7786 


^ 


•4739 


•5104 


•5468 


•5833 


.6197 


.6562 


.6926 


.7291 


•7^55 


.8020 


.8384 


H 


.5078 


•5468 


.5859 


.6250 


.6640 


•7031 


.7422 


.7812 


.8203 


.8593 


.8984 


I 


.5416 


.5833 


.6249 


.6666 


.7082 


.7500 


.7917 


•8333 


.8750 


.9166 


•9583 



TAPERS AND DOVETAILS 

MEASURING TAPERS 
An Accurate Taper Gage 

The gage illustrated in Fig. i is an exceedingly accurate device 
for the gaging of tapers. 

It is evident that if two round disks of unequal diameter are placed 
on a surface plate a certain distance apart, two straight-edges touch- 
It is also evident 




Fig. I. — Accurate Taper Gage 

that with the measuring instruments now in use it is a simple matter 
to measure accurately the diameters of the two disks, and the dis- 
tance these disks are apart. These three dimensions accurately and 
positively determine the taper represented by the straigh .-edges 
touching the rolls. If a record is made of these three dimensions 
these conditions can be reproduced at any time, thus making it pos- 
sible to duplicate a taper piece even though the part may not at 
the time be accessible. 

The formulas on the following pages may be of service in connec- 
tion with a gage of this character: 

341 



342 



TAPERS AND DOVETAILS 



.///////////.//^^^^ ^ 




Taper per Foot =% 
FIG. 2 




Taper per Poot ■■ 
FIG. 3 





APPLICATIONS OF FORMUt^AS 343 

Formulas for Use in Connection with Taper Gage 
To find Center Distance (/), refer to Fig. 2. 
, R 



y. + . 



t 
To find Disk Diameters, refer to Fig. 3. 



^[Jl^+ib- ay + (& + a) I 



Dia. Small Disk ^ 2 r 



R 



^Jl^+ib-ay- (b-aU 



Dia. Large Disk = 2 R 

To find Taper Per Foot (2"), refer to Fig. 4. 

r = 24 



Vi'-{R- ry, 



To find Width of Opening at Ends, refer to Fig. 5. 



Width of opening at Small End = 2 a. 



\ l + (R-r) 



Width of Opening at Large End = 2 b. 

Applications of Formulas 
To Find Center Distance Between Disks 

Suppose there are two disks as shown in Fig. 2, whose diameters 
are respectively ij and i inch. It is desired to construct a taper of 
f to the foot and the center distance / between disks must be deter- 
mined in order that the gage jaws when touching both disks shall 
give that taper. 

Let R = radius of large disk, or 0.625 inch. 
r = radius of small disk, or 0.500 inch. 
t = taper per inch on side, or 

= 0.03125 mch. 

24 ^ ^ 



344 TAPERS AND DOVETAILS 



Then _ R 



7^\/' + '^ 



3.03125 Y 



000976 = 4 X 1.0005 = 4.002 inches. 



To Find Disk Diameters 

Suppose the gage jaws are to be set as in Fig. 3 for a three-inch 
per foot taper whose length is to be four inches. The small end is 
to be exactly J inch and the large end for this taper will, therefore, 
be I J inches. What diameter must the disks be made so that when 
the jaws are in contact with them and the distance L over the disks 
measures 4 inches, the taper will be exactly three inches per foot? 
Here a represents ^ the width of opening at the small end, and h one 
half the width of opening at the large end. The radius of the small 
disk may be found by the formula: 



iW 



Then 



r = i{i/ L^+{b~ay+ (b-a)l. 



16 + 0.25 + 0.5 



= 0.0625 (4.0311 + 0.5) = 0.2832. 
Diameter small disk = 0.2832 inch X 2 == 0.5664 inch. 
For the large disk: 




ay - (b-a)}. 
16 + 0.25 - 0.5 



Then 



4 

= 0.1875 (4-0311 - 0.5) = 0.6621. 
Diameter large disk ^ 0.6621 inch X 2 = 1.3242 inches. 

To Find Taper Per Foot 

In duplicating a taper the gage jaws may be set to the model and 
by placing between the jaws a pair of disks whose diameters are 
known the taper per foot may be readily found. For example, the 
jaws in Fig. 4 are set to a certain model, two disks 0.9 and i.i inch 
diam.eter are placed between them and the distance over the disks 
measured, from which dimension / (which is 3.5 inches) is readily 
found by subtracting half the diameters of the disks. Here / repre- 
sents the center distance as in Fig. 2. To determine the taper pei 
foot which may be represented by T, the formula is: 



^Wi'- (R-ryl 



WIDTH OF GAGE OPENING 345 

Then 

r = 24 f "^ ] = 24 (-^] = 0.684 

VV 12.25 -0.01/ \3A9^5J 

Taper per foot = 0.684 inch. 



To Find Width of Opening at Ends 

If, with the ends of the gage jaws flush with a hne tangent to the 
disk peripheries as in Fig. 5, it is required to find the width of the 
opening at the small end where a represents one half that width, 
the follo^ving formula may be applied, the disks being as in the last 
example o.g and i.i inch diameter respectively, and the center dis- 
tance 3.5 inches: 



Then 



0.45 



11- {R 


-r} 




/ l+iR- 


-r) 




ls-S-i 


•55 - 


.45) 


/ 3-5 + ( 


•55 - 


•45) 



0.45 \/'^ = °-45 V .94444 = .4373 



0.4373 inch X 2 = 0.8746 inch width of opening at small end of gage. 

Similarly the width of opening at the large end of the gage may be 
found as follows, where b = half the width of the large end. 



Then 



V 3-4 



55 - -45) 



55 - 45) 



■55 — 1.05882 = .56595 
0-56595 inch X 2 = 1.1319 inch ^ width of opening at large end. 



346 



TAPERS AND DOVETAILS 




BROWN & SHARPE TAPERS 



347 



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34« 



TAPERS AND DOVETAILS 




MORSE TAPERS 



349 



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< 


"£ 


H-* 


< 


"^H 


C*0 


^ 


m!-* 




anSuox 
JO ssau^iDiqx 


- 


■"!« 




H'* 


H- 


,-.1=0 


IC|W 


ml-* 


iHiCO 




anSuox p -t^iq 


'^ 




^ 
fO 


r^lM 




m|«i 




N 






anSuox Jo qiSua^; 


H 


H-* 


«lco 


H2 


=^ES 


..-.loo 


C5N 


M 


ccw. 




-X3X JO qipiAV 


^ 


v§ 




o 


CO 


CO 


lO 




l-O 

CO 

M 
l-i 




-X3;5j JO qjSuJ'X 


kJ 


o-J'^ 


«N 


H«i 


«^ 


wM 


r*, 


ml-* 

M 


lOlXI 
01 




oj la^Dos JO pua 


t4 




-12 




H2 

CO 


CO 




t^ 


rH|(N 

OS 




spH p ^^fi^a 


ffi 




H2 


01 


CO 




lO 


coloo 
1-^ 


rHiOO 

o 




JO qjSua^ 3101LVV 


PQ 




0« 


-loo 
CO 


CO 








«;;ao 






f^ 


C^ 


<N 




"!2 

CO 




H2 

VO 









JO pua }T3 -BIQ 


<1 






^ 


00 


M 

CO 


00 


1 
c5 


C) 

CO 




pua n^tus 

}i3 Snij JO -iiia 


Q 




CO 


in 




q 


lO 


c< 






jadBx JO -ON^ 




O 


w 


N 


CO 


^ 


vn 


O 


- 





3SO 



TAPERS AND DOVETAILS 





(5 


M 


^ 






43 




O 


(U 






el 


<U 


>% 






T) 


tc^ 




be 


S 


v. 


^ 


S 




c3 


(U 




O 




<s3 TJ 






(U 


4i 


en ij 


rt 


i^ 


hf> 


-s 


X! 


C 




t/3 


^ 


-5 










O 




43 
tn 


O 


Xi 


^x. 


C5 


> 


CO- 


^ 


x) 




«5 


V 


^ 


ri:3 


hfl 


tn 




C 


C 


7^ 


O 


"^ 




tn 


V) 


o 


rt 


3 


a 






c 


;-i 


^ 


iS 


ft! 




1 
•5b 


i 


-i2 . 








S 


be 


'C ^ 


CO d 


<u 




^ 


^ 


-^ 


-^ 







MORSE TAPERS, SHORT SHANKS 



351 





X33 JO jaquinj^ 


OHP<^o^>oor^ 


qDuj i3d JadBj^ 


=§ ^ ^ S to ^ "§ 
'NOOOM^^lNOl 


500J J9d ladBx 


100 <N t^ roOOio 

N Q OlN t^CS (N 


AvjAAa-^ oj 
:j3i[D0S JO pua 


M 


H'M -<M t-"l ^'N ^:> -*l to 


1 


X'BAlX3;2 

JO qiSaai 


i-l 


»i- :!S "5 ■=£ -■- "'^ "1" 

H H w N Ol CO 


X-BAiX9;3; JO q)pi,W. 


^ 


fOO CO >O00 w VO r-- H M VO fOOO O "+ 


to 

1 


9nSuojL JO sntpB^ 


rt 


"S -J^ -^ "K "^ -1. ^ n« 


3n3uox 

JO J313UI-BIQ 


T3 


00 l-l I0r0<^f000 0> 

int-r^oo Noo <Nvo 

•NtOVOt-O'^l-Ht- 


anSuox 
Joj inw JO -piJ^ 


« 


"S -I" =--p •=£ "1" H« »1« nw 


anSuox Jo q?Sn9']; 


H 


-<^ -S ^S »S -"«> '^^ -'- '*' 
M M 


anSuox 
JO ssaui^Diqx 


« 


00 a w "to Ov M Tl-vo » M CO M fO r- 
ooco mor^i^OO IN ci 0>0 tirjiN <N 

w M <N <N CO "p -^ >ovo VO ON q IN 1^; vq >o 


q^daa 
3n[ji pjTjpuB^s 


- 


M H CS cTcO'tlOt^ 


310H JO q^daa 


W 


Sn "S H2 '^i^' -^'h "S "I-* "S 

WMCMNfOM-lOCO 


CO 


qjdaa ^^qs 


(n 


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jjuBqs JO . 
q;Su3T apqAV * 


pq 


^S "S oE -« ^ -« ^ :S 

M<N<Nro^'OJ--0> 


131100S JO pu3 it; -uiBia 


< 


V0100COMOO-+0 
ro-ft-^OviN '~r"t" 

M P-i <N CO 


pu3 n^ras 
;b 2nid JO -uiBia 


Q 


M 00 ^ IN l-l t^ 
t^OO MVO ro ^ 
IN rovooo q upiNOO 




J3dBX JO jaqranjsj 




OMC^co-tiovor^ 



352 



TAPERS AND DOVETAILS 

k— -J— H<- 




The Standard Tool Company's Standard Taper Shanks 













Length 




No. of 
Taper 


Diameter 


Diameter 


Total 


Depth 


Tongue 


Thickness 


Small End 


Large End 


Length of 


Hole 


to End 


of 


of Shank 


of Shank 


Shank 


in Socket 


Socket 


Tongue 












Hole 






A 


B 


c 


D 


E 


F 


O 


.2406 


.3626 


2H 


23^2 


A 


3\ 


I 


.3533 


.4814 


2-% 


2f6 

2f 


? 


el 


2 


•5531 


.7099 


3- 


♦ 


J 


3 


• 7529 


.9472 


3I 


3l 


f^ 


fl • 


4 


.9908 


1.2438 


4l 


4f 


1 


if 


5 


1.4390 


1.7605 


6| 


4 


f 


f 


6 


2.0638 


2.5104 


8tV 


7f 


8 


\ 


7 


2.6849 


3.2903 


iif 


io| 


li 


i| 



No. of 
Taper 


Width 


End of 


Length 


Diameter 


Taper 


Taper 


of 


Socket of 


of 


of 


per 


per 


Keyway 


Keyway 


Keyway 


Socket 


Foot 


Inch 




G 


H 


J 


: K 









H 


lit 


T% 


t\ 


.625 


.05208 


I 


3^2 


2tV 


1 


If 


.600 


.05000 




il 


2I 


il 


itV 


.602 


.05016 


3 




3tV 


li 


lT« 


.602 


.05016 


4 


1 - 


3l 


itV 


IH 


.623 


.05191 


5 


h 


4lf 


If 


2tV 


.630 


.05250 


6 


n 


7 


2i 


2! 


.626 


.05216 


7 


l6\' 


9l • 


2I 




.625 


.05208 



STANDARD TOOL COMPANY'S TAPERS 



353 



^ _ w///w//My//^'\ 

"I 



<\ \ ) 



Y^'^-M^yW<y^W^ 



-e- 




b'fe 



The Standard Tool Company's Short Taper 



No. of 
Taper 


Diameter 
SmaU End 
of Shank 


Diameter 
Large End 
of Shank 


Total 
Length 
of Shank 


Depth 

Hole 

in Socket 


Length 
Tongue 
to End 
Socket 
Hole 


Thickness 

of 

Tongue 




A 


B 


c 


D 


E 


F 


I 

2 

3 


.378 
.587 
.800 


.484 
.706 • 
.941 


2\ 


if 




\ 


4 


1.050 


1.244 


3f 


3 


F 


1 


5 
6 

7 


1-515 
2.169 
2.815 


1.757 
2.501. 
3.283 


4f 
6f 
9 


3I 


1 

I 


I 

'1 



No. 


Width 


End of 


Length 


Diameter 


Taper 


Taper 


of 


of 


Socket to 


of 


of 


per 


per 


Taper 


Keyway 


Keyway 


Kejnvay 


Socket 


Foot 


Inch 




G 


H 


J 


K 






I 


.263 


If 


f 


II 


.600 


.0500 


2 


.388 


If 


I 


ItV 


.602 


.05016 


3 


.520 


2 


li 


ifV 


.602 


.05016 


4 


•645 


2H 


i| 


^\^ 


.623 


.05191 


5 


1.020 


z\ 


2 


2tV 


.630 


.0525 


6 


1.270 


4f 


2\ 


2| 


.626 


.05216 


7 


1.520 


7 


3 




.625 


.05208 



THE STANDARD TOOL GO'S. SHORT TAPER SHANKS 

The table shows the short taper shanks of the Standard Tool 
Company for giving a tang of increased strength. 

Sockets and sleeves are furnished, made with the outside taper 
to fit the regular taper of spindles of drill presses; the inner taper 
being suitable for the short shanks and also made with both outside 
and inside taper, conforming to the new standard, and these latter 
interchange or nest into each other. 



354 



TAPERS AND DOVETAILS 



THE REED TAPER 

The F, E. Reed Company, Worcester, Mass., uses in its lathe 
spindles the i in 20 taper (0.6 per foot) which the Jarno system is 
based on. The diameters of the Reed tapers, however, differ from 
the Jarno, and the lengths in most cases are somewhat less. The 
dimensions are given in the table below. 




I I 

F. E. Reed Lathe Center Tapers 

TAPER per foot = 0.6 INCH. TAPER PER INCH = O.05 INCH 



Size 
of 


Dia. of Small 
End of 
Taper 


Length of 
Taper 


Size 

of 

Lathe 


Dia.ofSmaU 
End of 
Taper 


Length of 
Taper 


Lathe 


A 


B 


A 


B 


12" 

14" 

16" 

Special 16" 

18" 


1% 
if 


3I 
4l 
4h 
4| 
5tV 


20" 
22" 
24'' 
27" 
30" 


li 
li 
If 
If 
2 


5t\ 



THE JARNO TAPER 

While the majority of American tool builders use the Brown & 
Sharpe taper in their milling-machine spindles and the Morse taper 
in their lathes, a number of firms, among them the Pratt & Whitney 
Company, Hartford, Conn., and the Norton Grinding Company, 
Worcester, Mass., have adopted the "Jarno" taper, the proportions 
of which are given in the accompanying table. In this system the 
taper of which is 0.6 inch per foot or i in 20, the number of the 
taper is the key by which all the dimensions are immediately deter- 



JARNO TAPERS 



355 



mined without the necessity even of referring to the table. That is, 
the number of the taper is the number of tenths of an inch in diam- 
eter at the small end, the number of eighths of an inch at the large 
end, and the number of halves of an inch in length or depth. For 
example: the No. 6 taper is six eighths (f) inch diameter at large 
end, six tenths (j^) diameter at the small end and six halves (3 
inches) in length. Similarly, the No. 16 taper is V'-, or 2 inches 
diameter at the large end; }f or 1.6 inches at the small end; ^^ or 
8 inches in length. 




Jarno Tapers 
taper per foot = 0.6 inch. taper per inch = o.05 inch. 

No. of Taper 



Dia. Large End 



Dia. Small End = 



Length of Taper 



No. of Taper 

10 
No. of Taper 





Dia. Large 


Dia. Small 


Length of 




Dia. Large 


Dia. Small 


Length of 


No. 


End 


End 


Taper 


No. 


End 


End 


Taper 


of 








of 
Taper 








Taper 
















A 


B 


C 




A 


B 


C 


I 


.125 


.10 


•5 


ir 


I-37S 


1. 10 


5-5 


2 


.250 


.20 


I- 


12 


1.500 


1.20 


6.0 


3 


•375 


•30 


1-5 


13 


1.625 


1.30 


6-5 


4 


.500 


.40 


2.0 


14 


1-750 


1.40 


7.0 


5 


.625 


.50 


2.5 


15 


1.875 


1.50 


7-5 


6 


•750 


.60 


3-0 


16 


2,000 


1.60 


8.0 


7 


.875 


.70 


3-5 


17 


2.125 


1.70 


8.5 


8 


1. 000 


.80 


4.0 


18 


2.250 


1.80 


9.0 


9 


1.125 


.90 


4.5 


19 


2-375 


1.90 


9-5 


10 


1.250 


1. 00 


5-0 


20 


2.500 


2.00 


lO.O 



356 



TAPERS AND DOVETAILS 
-D — 




Sellers Tapers 



Q 


t5M 

II 


•go 

-3^ 








1" 
II 





fi 


-ot 






1 


"o 


•^^ 


SB 


■5^ c 


■5S 


^^B 


■5^^ 


^-.^ 


^f^ 


^^ 


J3 






























rt 


.26 




S»?^ 


T^Q 


SO 


.2^^ 


?,-5'c 


'ix^C 


.■2.S 


^.£ 


;iJ 


•^ 


Q 


a 


^ 


H 


M 


Q 


J 


< 


!^ 


Q 


?: 


K 


A 


B 


^ ! 




D 

2A 


E 


F 




G 


H 


I 


K 


i 


i 


2} 


4i 


6i 


u 


3 

T6 


3-7° 


^\ 


^4 


ITT 


W^T 


A 






4i 


6i 


- (t 






3.70 


" 








i 






4i 


7 


" 




<t 


3-70 


<( 




" 




tV 


« 




Si 


7i 


" 




tt 


3-70 


" 




(( 


(( 








Si 


8 


" 




tc 


=^•32 


" 




" 




T^6- 


ii 


2f 


6i 


8 


2| 




i 


5.32 


i 


ifV 


fi^T 


u 


f 


" 




6i 


9* 


" 






K.32 


" 








H 


(( 




6:f 


9* 


" 




" 


6.24 


<c 




" 


tt 


i 


« 




7i 


10 


u 




" 


6.24 


<c 




<< 


" 


H 


<< 




7i 


10 


(( 




<( 


6.24 


" 




" 


" 


i 


i 


3i 


8 


II* 


^H 




^5.- 


7.28 


" 




" 




H 




" 


8 


iH 


" 




i( 


7.28 


" 




" 






" 




8^ 


12 


" 






9-50 


" 








ItV 


ei 




^ 


12 


" 




« 


" 


(C 




C( 


il 


li 


li 


4* 


9 


13* 


4l 


M. 


f 


(( 


A 




u 


n 


lA 






9 


i3i 
















" 


li 






9 


i3i 


" 












" 


" 


ifV 






9 


13* 














" 




i^ 


<< 




9* 


14 


" 




« 


(C 


<c 




" 


" 


ItV 


" 




9* 


14 


<c 




(C 


C( 


<c 




" 




I* 


" 




10 


14* 


tt 




(t 


" 


" 




" 




irk 






10 


14* 


(C 




(C 


" 


" 








i| 


If 


6h 


10 


i6i 


6f 


li 


tV 


13-72 


1 

4 


1V2 


if 


H 


iH 






10 


16* 










" 








i| 


(C 




10* 


17 


" 




(( 


(C 


a 




« 


" 


i+f 


(C 




10* 


17 


" 




(C 


il 


" 




(( 


" 


4 


<c 




II 


17* 






<( 


" 


" 




" 




iH 


" 




II 


i7i 


" 




" 


" 


" 






" 


2 


11 




Hi 


18 



















TAPER PINS AND REAMERS 



357 



THE SELLERS' TAPER 

The system of tapers used by William Sellers & Company, Inc., 
of Philadelphia, Pa., in lathes, drilling and boring machines, is 
given in the preceding table. The taper is | inch per foot and each 
size of taper is splined as shown for a key the dimensions of which 
are included in the table. The 'pitch of the spiral for the drills used 
by the company is also included. 



TAPER PINS AND REAMERS 



H: 



Taper Reamers and Pins 

(pratt & whitney co.) 

Taper = | inch per foot or .0208 inch per inch 



c 


1 


£■31 


S 





of 




k 


Dprox. Frac- 
tional Size at 
Large End 
of Pin 


In 


Q 


Q 


H 


c75 


p 


< 





0.135" 


.162'' 


ItV 


2" 


28 


l'' 


.156" 


tV 


I 


.146'' 


.179'' 


^Tk" 


2r 


25 


ir 


.17a" 


w 


2 


.162'' 


.200'' 


iir 


2H" 


19 


ir 


.193" 


tV 


3 


.18 f 


.226" 


2^" 


f 


12 


ir 


.219" 


^" 


4 


.208" 


.257'' 


2r 


3iV' 


3 


2" 


.250" 


r 


5 


.240'' 


.300" 


2'f 


4r 


i 


2i 


.289" 




6 


.279" 


•354'' 


3l" 


5" 


/t 


3F 


.341" 


ii" 


7 


.331'' 


.423" 


4tV' 


6tV' 


++ 


3r 


.409" 


w 


8 


.398'' 


.507'' 


.Si" 


7^^ 


H 


4r 


•492" 


r 


9 


.482- 


.6og" 


6r 


H" 


6 4 


si" 


.591" 


-H" 


10 


.581'' 


.727" 


f 


9¥ 




6" 


.706" 


2 3// 


II 


.706'' 


.878" 


8i" 


iir 


ft 


7i" 


■^57' 


■ff" 


12 


.842" 


1.050" 


10" 


i3r 


If 


w 


I.Olf 


i«V' 


13 


1.009" 


1.259" 


12" 


16" 


I^V 


lor 


1.233" 


lir 



These reamer sizes are so proportioned that each overlaps the 
3Jze sinaller about ^ inch 



358 



TAPERS AND DOVETAILS 







Table of Drill Sizes 


FOR 


Taper Pins 




DrUl Sizes for Taper Pins 


No. 
of Pin 


L 


D 


d 


No. of 
Drill 


T'Ua 


table 


gives the drill sizes for 












ine 












taper 


pins ranging in lengths by i 1 








0.3829" 


IS" 


inch from No. o, f inch long, to No. 




^U 


0.409" 


lo, 6 inches long. The diameter of 


7 


I 2 
If" 


0.409" 


0.3777" 


" 


the small end of the pin for each 


7 . 


0.409" 


0.3725 




length 
with t 


is gi\ 


en in the fourth column 




2 " 
2j" 

2¥' 


0.409" 


0.3673" 


-" 


le drill size in the fifth column. 




0.409" 
0.409" 


0.3621" 
0.3569" 


P" 










2?" 


0.409" 


0.3517" 


s^" 










3 " 

3- 

3-" 


0.409" 
0.409" 
0.409" 


0.3465" 
0.3413" 
0.3361" 


1 




H 


~~IZI3*' 




4— 


— ^— i* 




3- 


0.409" 


0.3309" 


lY 




1 


8 


li-" 


0.492" 


0.466 " 


W 




-^^j5_Length«fPinX.25 


8 


ir 


0.492" 


0.4608" 


l" 




8 


If" 


0.492" 


0.4555" 


§1" 






8 


2 " 


0.492" 


0.4503" 


«r 








8 


2i" 


0.492" 


0.4451" 


It 








8 
8 


^}" 


0.492" 
0.492" 


0.4399^^ 


f' 












0.4347 


No. 


L 


D 


d 


No. of 


8 


3 


0.492" 


0.4295 


1%" 


Pin 


Drill 


8 


^K 


0.492" 


0.4243" 


%%!> 












8 
8 


§ 


0.492" 
0.492" 


0.4191 
0.4139." 


_xn 












2Z» 


o 


r 


0.156" 


0.1404" 


28 


8 


4 " 


0.492" 


. 0.4087" 


J/' 


o 


I " 


0.156" 


0.1352" 


29 


8 


4? 


0.492" 


0.4035 


.r 


I 


r 


0.172" 


0.1564" 


22 


8 


42" 


0.492" 


0.3982" 


K 


I 




0.172" 


0.1512" 


24 


9 


1/ 


0.591" 


0.5597" 


tY 


I 


T-" 


0.172" 


0.146 " 


26 


9 


^*: 


0.591" 


0.5545" 


ii" 


2 


f" 


0.193" 


0.1774" 


16 


9 


2 " 


0.591" 


O.S493" 


II" 


2 


I " 


0.193" 


0.1722" 


17 


9 


21" 


0.591" 


0.5441" 


§4" 


2 


I-" 


0.193" 


0.167 " 


18 


9 


25" 


0.591" 


0.5389" 


ii" 


2 


I-" 


0.193 


0.1618" 


20 


9 


2/ 


0.591" 


0.5337" 


1|" 


3 


_// 


0.219" 


0.2034" 


6 


9 


3 " 


0.591" 


0.5285" 


W 


3 


I " 


0.219" 


0.1982" 


8 


9 


31" 


0.591" 


0.5233" 


■kl" 


3 


I-" 


0.219" 


0.193 " 


10 


9 


3r 


0.591" 


0.5181" 


-r 


3 


I-" 


0.219" 


0.1878" 


12 


9 


3f" 


0.591" 


0.5129" 


% 


3 


I-" 


0.219" 


0.1825" 


^4 „ 


9 


4 


0.591" 


0.5077" 


ir 


4 


-" 


0.250" 


0.2344" 


if 


9 


41" 


0.591" 


0.5025" 




4 


I " 


0.250" 


0.2292" 


Br 


9 


4^; 


0.591" 


0.4972" 


1" 


4 


T-" 


0.250" 


0.224 " 


I 


9 


4f" 


0.591" 


0.4929" 


5" 


4 


li" 


0.250" 


0.2187" 


2 


9 


5 " 


0.591" 


0.4868" 


iJ" 


4 


if" 


0.250" 


0.2135" 


3 


9 


sr 


0.591" 


0.4816" 


K 


4 


2 " 


0.250" 


0.2083" 


4 


9 


sr 


0.591" 


0.4764" 


31* 


5 


r 


0.289" 


0.2734" 


ii" 


10 


li" 


0.706" 


0.6747" 


II" 


s 




0.289" 


0.2682" 


44" 


10 


If" 


0.706" 


0.6695" 


K 


5 


I-" 


0.289" 


0.263 " 


U" 


10 


2 " 


0.706" 


0.6643" 


tr 


s 


I-" 


0.289" 


0.2577" 


i" 


10 


2j" 


0.706" 


0.6591" 


w 


5 


I-" 


0.289" 


0.2525" 


4 


10 


2§" 


0.706" 


0.6539" 


K 


s 




0.289" 


0.2473" 


r 


10 


2f" 


0.706" 


0.6487" 


iifl 


s 


21" 


O.2S9" 


0.2421" 


X5" 


10 


3 " 


0.706" 


0.643 s" 


ei" 


6 


f" 


0.341" 


0.3254" 


II" 


10 


3i" 


0.706" 


0.6383" 


K 


6 


I " 


0.341" 


0.3201" 


B" 


10 


3*" 


0.706" 


0.6331" 


ir 


6 


I-" 


0.341" 


0.315 " 


iV 


10 


3f" 


0.706" 


0.6278" 




6 


I-" 


0.341" 


0.310 " 


iV 


10 


4 " 


0.706" 


0.6226" 


f" 


6 


I-" 


0.341" 


0.3045" 


H" 


10 


4-" 


0.706" 


0.6174" 


1" 


6 


2 " 


0.341" 


0.2994" 


41" 


10 


4-" 


0.706" 


0.6122" 


ir 


6 


2-" 


0.341" 


0.2941" 


H" 


10 


4 " 


0.706" 


0.6078" 


K 


6 


2-" 


0.341" 


0.2889" 


^%" 


10 


5 " 


0.706" 


0.6018" 


%r 


6 


2r 


0.341" 


0.2837" 


.%" 


10 


S-" 


0.706" 


0.5966" 


\r 


6 




0.341" 


0.2785" 


uV 


10 


^i/ 


0.706" 


0.5914" 


4r 


6 


3r 


0.341" 


0.2733" 


hi" 


10 




0.706" 


0.5862" 


\%" 


7 




0.409" 


0.3881" 


ir 


10 


6*" 


0.706" 


0.581 " 





ORDNANCE TAPER PINS 



359 



" ^ .2 S 

Is i^ 



If 



li 



c c:'5"«j3 



« a 
:S5 












•5 iJ 



O a My 

S ^ c 
rt-d • o'a 

<^t3 „ i2 „ 
O ="*-—« 

a5 ort ^ 



o-^ S-U-, <u_ S !3 



b o^_c d ^ 



o a 

.S3 2-^= aa. »:> 

g.t^g.fl'^d- j^: 
g^^^ga-^-d^ 

§.d^^^^8sa 

H .KJ3<ua>j5^4> 






Eo 





















rr 


^ 


■* 


^ 






































H 










s 


l-T 


t^ 


^. 












'^ 


% 








<n 


in 


in 


in 












2 
















CO 




























































< 










CO 




CO 














1 






CO 


CO 


CO 


CO 


w 
















































l~ 




1^ 
















3D 


S 












(M 




Q 














in 


^, 


u-5 


in 


in 


in 




m 






























H 








< 


!^ 
























C4 


?i 




Vi 






i 'f 








c. 


C-, 


<M 


C^l 


Cl 


OJ 


CM 










s 


in 


i2 


t^ 


t^ 


o 




































M 










U5 


\r\ 


in 


in 


in 


in 






^°- 


- ' — 














rt 








•-< 








Q 








^ 


2 




^ 


"i 


B 








4 






o 


















^ 


3 




S 


o 






^ 


„ 










°o 


ta 






















u 


st^ 
























'^, 


*-! 










^ 


« 




.n 




in 






% 


s 


QhS 














i^ 












c 








o 


o 


o 


o 


o 


° 


o 






Ln 


U5 


sis 




















o 


o 








s 


s 


o 


u. 


lO 








^ 


^ 


;Iq« 






=> 


o 


° 




o 


° 












Q 


S 


g 


i 


3 


U3 


^ 


:f 


S 








in 






























^ 


* 


o 


o 


=" 


° 


o 


o 


° 


o 


o 


o 


•a 






a 

2 

J3 


« 




? 








!a 


in 


vn 










.s 






























































=^ 








o 


o 




o 


o 


-* 


i-i 


^ 


_ 


































H 
























m — > 


:^^° 


?^: 








^ 


^ 


-, 


t2 


in 


CO 




.2 


UJ 


< 








o 


S 


S 


S 


£4 


^ 


S 


^ 














o 


o 


o 


fS 


^ 




-5 


1 \ 


CJ 


























^ 1 /^ 


"\\ 






CO 


e 

S 


ya 




w 


in 


in 


in 


in 


o 


i 


|a 


; 








a 


o 


-' 


'-' 




o\ 


" 


"* 


to 


05 




-r^ 




H 




a 




















ff" 


H-c 


ci 


M 


f^ 


CO 


lO 


l~ 




in 






■n 


in 




\^ 


fl S 


^ 






o 


o 


= 


'"' 








^ 


CO 


a ei-o4 


I i 






K 


s 




















if 


^=Q 




« 


g 




















/^i 


\ 


izi 




a 


•i; 




m 


in 


t~ 




m 






in 


^ / ^ 


X > 


<1 




UJ 


I 










M 


,-1 


C^J 




^ 


^ / 


\ 


H 




ij 






















E? I 


) 


c3 






rt 




















.K 


i^ 


g 


< 
H 


Q 


o 


1 


2 

6 


s 

o 


1 


03 

o 


d 


d 


i 

o 


"t 


p. 


S 


1 






o 




^ 




ao 




" 




o 


H 


A 


^ 








- 




to 




3 







36o 



TAPERS AND DOVETAILS 



Tapers from jL to i| inch per Foot 
amount of taper for lengths up to 24 entches 





Taper per Foot 




•6f2 






11 


in 


b\ 


i 


i 


f 


i 


f 


f 


I 


li 


V 


.0002 


.0002 


.0003 


.coo 7 


.0010 


.0013 


.0016 


.0020 


.0026 


.0033 


tV 


.0003 


.0005 


.0007 


.0013 


.0020 


.0026 


.0033 


.0039 


.0052 


. .0065 


i 


.0007 


.0010 


.0013 


.0026 


.0039 


.0052 


.0065 


.0078 


.0104 


.0130 


P 


.0010 


.0015 


.0020 


.0039 


.0059 


.0078 


.0098 


.0117 


.0156 


.0195 


i 


.0013 


.0020 


.0026 


.0052 


.0078 


.0104 


.0130 


.0136 


.0208 


.0260 


f 


.0016 


.0024 


.0033 


.0065 


.0098 


.0130 


.0163 


.0195 


.0260 


.0326 


t 


.0020 


.0029 


.0039 


.0078 


.0117 


.0156 


.0195 


.0234 


.0312 


.0391 


f^ 


.0023 


.0034 


.0046 


.0091 


•0137 


.0182 


.0228 


.0273 


•0365 


.0456 


i 


.0026 


.0039 


.0052 


.0104 


.0156 


.0208 


.0260 


.0312 


.0417 


.0521 


1^ 


.0029 


.0044 


.0059 


.0117 


.0176 


.0234 


.0293 


•0352 


.0469 


.0586 


f 


•0033 


.0049 


.0065 


.0130 


.0195 


.0260 


.0326 


.0391 


.0521 


.0651 


ii 


.0036 


.0054 


.0072 


.0143 


,0215 


.0286 


•0358 


.0430 


•0573 


.0716 


.0039 


.0059 


.0078 


.0156 


.0234 


.0312 


.0391 


.0469 


.0625 


.0781 


1^ 


.0042 


.0063 


.0085 


.0169 


.0254 


.0339 


.0423 


.0508 


.0677 


.0846 


.0046 


.0068 


.0091 


.0182 


.0273 


•0365 


.0456 


•0547 


.0729 


.0911 


H 


.0049 


.0073 


.0098 


.0195 


.0293 


.0391 


.0488 


.0586 


.0781 


.0977 


I 


.0052 


.0078 


.0104 


.0208 


.0312 


.0417 


.0521 


.0625 


•0833 


.1042 


2 


.0104 


.0156 


.0208 


.0417 


.0625 


.0833 


.1042 


.125 


.1667 


.2083 


3 


.0156 


.0234 


.0312 


.0625 


•0937 


.i2c;o 


.1562 


•1875 


.250 


•3125 


4 


.0208 


.0312 


.0417 


•0833 


.125 


.1667 


.2083 


.250 


■3333 


.4167 


5 


.0260 


.0391 


.0521 


.1042 


.1562 


.2083 


.2604 


•3125 


.4167 


.5208 


6 


.0312 


.0469 


.0625 


.125 


.1875 


.250 


•3125 


•375 


.500 


•625 


7 


•0365 


•0547 


.0729 


.1458 


.2187 


.2917 


.3646 


•4375 


.5833 


.7292 


8 


.0417 


.0625 


.0833 


.1667 


.250 


■3333 


.4167 


.500 


.6667 


•8333 


9. 


.0469 


.0703 


•0937 


.1875 


.2812 


•375 


.4687 


•5625 


•750 


•9375 


10 


.0521 


.0781 


.1042 


.2083 


•3125 


.4167 


.5208 


.625 


•^333 


1. 041 7 


II 


•0573 


.0859 


.1146 


.2292 


.3437 


•4583 


•5729 


.6875 


.9167 


1.1458 


12 


.0625 


•0937 


.125 


.250 


•375 


.500 


.625 


•750 


1. 000 


1.250 


13 


.0677 


.1016 


•1354 


.2708 


.4062 


•5417 


.6771 


•8125 


i^o833 


1^3542 


14 


.0729 


.1094 


.1458 


.2917 


•4375 


.5833 


.7292 


.875 


1. 1667 


1.4583 


15 


.0781 


.1172 


.1562 


•3125 


.4687 


.625 


.7812 


•9375 


1.250 


1-5625 


16 


.0833 


.125 


.1667 


■3333 


.500 


.6667 


.8333 


r.ooo 


^■3333 


1.6667 


17 


.0885 


.1328 


.1771 


•3542' 


•5312 


.7083 


.8854 


1.0625 


1.4167 


1.7708 


18 


•0937 


.1406 


.1875 


•3750 


•5625 


•750 


•9375 


1.125 


1.500 


1.875 


19 


.0990 


.1484 


.1979 


•3958 


•5937 


.7917 


.9896 


1.1875 


1-5833 


1.9792 


20 


.1042 


.1562 


.2083 


.4167 


.625 


.8333 


1. 041 7 


1.250 


1.6667 


2.0833 


21 


.1094 


.1641 .2187 


•4375 


.6562 


.875 


^•0937 


1^3125 


i^75o 


2.1875 


22 


.1146 


.1719 .2292 


.4583 


.6875 


.9167 


1.1458 


^•375 


1-8333 


2.2917 


23 


.1198 


.1797 


.2396 


.4792 


.7187 


•9583 


1.1970 


1-4375 


1.9167 


2.3958 


24 


.125 


•1875 


.250 


.500 


•750 


1. 000 


1.250 


1.500 


2.000 


2.500 



TAPERS AND CORRESPONDING ANGLES 3^1 

Tapers Per Foot in Inches and Corresponding Angles 





Included 


Angle with 




Included 


Angle with 


*-?! 


Angle 


Center 


Line 


"S 




Angle 




Center .Line 


s£ 












K^ 












H^ 


i 




J 


i 




J 


^7. 


1 


d 


i 


i 




1 


^^ 





4 


28 





2 


14 


I 


4 


46 


18 


2 


23 


9 


3V 





8 


58 





4 


29 


li 


5 


21 


44 


2 


40 


52 


T6 





17 


54 





8 


57 


il 


5 


57 


48 


2 


58 


54 


3% 





26 


52 





13 


26 


if 


6 


33 


26 


3 


16 


43 


^ 





35 


48 





17 


54 


li 


7 


9 


10 


3 


34 


35 


3\ 





44 


44 





22 


22 


if 


7 


44 


48 


3 


52 


24 


A 





53 


44 





26 


52 


if 


8 


20 


26 


4 


10 


13 


/l 


I 


2 


34 





31 


17 


i| 


8 


56 


2 


4 


28 


I 


f 


I 


II 


36 





35 


48 


2 


9 


31 


36 


4 


45 


48 


1^ 


I 


20 


30 





40 


15 


2i 


10 


42 


42 


5 


21 


21 


I! 


I 


29 


30 





44 


45 


2j 


II 


53 


36 


5 


56 


48 


H 


I 


38 


22 





49 


II 


2f 


13 


4 


24 


6 


32 


12 


.^, 


I 


47 


24 





53 


42 


3 


14 


15 





7 


7 


30 


M 


I 


56 


24 





58 


12 


3i 


15 


25 


24 


7 


42 


42 


j\ 


2 


5 


18 


I 


2 


39 


3J 


16 


35 


40 


8 


17 


50 


¥ 


2 


14 


16 




7 


8 


3f 


17 


45 


40 


8 


52 


50 


^ 


2 


23 


10 




II 


35 


4 


18 


55 


28 


9 


27 


44 


M 


2 


32 


4 




16 


2 


4i 


20 


5 


2 


10 


2 


31 


A 


2 


41 


4 




20 


32 


4j 


21 


14 


2 


10 


37 


I 


if 


2 


50 


2 




25 


I 


4f 


22 


23 


22 


II 


II 


41 


f 


2 


59 


42 




29 


51 


5 


23 


32 


12 


II 


46 


6 


fi 


3 


7 


56 




33 


58 


5i 


24 


40 


42 


12 


20 


21 


T6 


3 


16 


54 




38 


27 


5i 


25 


48 


48 


12 


54 


24 


If 


3- 


25 


50 




42 


55 


5i 


26 


56 


46 


13 


28 


23 


f 


3 


34 


44 




47 


22 


6 


28 


4 


2 


14 


2 


I 


25 


3 


43 


44 




51 


52 


6i 


29 


II 


34 


14 


35 


47 


If 


3 


52 


38 




56 


19 


6^- 


30 


18 


26 


15 


9 


13 


fi 


4 


I 


36 


2 





48 


6| 


31 


25 


2 


15 


42 


31 


i 


4 


10 


32 


2 


5 


16 


7 


32 


31 


12 


16 


15 


36 


II 


4 


19 


34 


' 


9 


47 


7i 


33 


36 


40 


16 


48 


20 


H 


4 


28 


24 


2 


14 


12 


7^ 


34 


42 


30 


17 


21 


15 


ti 


4 


37 


20 


2 


18 


40 


7f 


35 


47 


32 


17 


53 


46 
















8 


36 


52 


12 


18 


26 


6 



362 



TAPERS AND DOVETAILS 



Table for Computing Tapers 
The Tabulated Quantities = Twice the Tangent of Half the Angle. 



Deg. 


0' 


10' 


20' 


30' 


40' 


50' 


60' 





.00000 


.00290 


.00582 


.00872 


. .01164 


.01454 


.01746 


I 


.01746 


.02036 


.02326 


.02618 


.02910 


.03200 


.03492 


2 


.03492 


•03782 


.04072 


.04364 


.04656 


.04946 


.05238 


3 


.05238 


.05528 


.05820 


.06110 


.06402 


.06692 


.06984 


4 


.06984 


.07276 


.07566 


.07858 


.08150 


.08440 


.08732 


5 


.08732 


.09024 


.09316 


.09606 


.09898 


.10190 


.10482 


6 


.10482 


.10774 


.11066 


.11356 


.11648 


.11940 


.12232 


7 


.12232 


.12524 


.12816 


.13108 


.13400 


.13694 


.13986 


8 


.13986 


.14278 


.14570 


.14862 


.15156 


.15448 


.15740 


9 


•15740 


' .16034 


.16326 


.16618 


.16912 


.17204 


.17498 


10 


.17498 


.17790 


.18084 


.18378 


.18670 


.18964 


.19258 


II 


.19258 


.19552 


.19846 


.20138 


.20432 


.20726 


.21020 


12 


.21020 


.21314 


.21610 


.21904 


.22198 


.22492 


.22788 


13 


.22788 


.23082 


.23376 


.23672 


.23966 


.24262 


.24556 


14 


.24556 


.24852 


.25148 


.25444 


.25738 


.26034 


.26330 


15 


.26330 


.26626 


.26922 


.27218 


.27516 


.27S12 


.28108 


16 


.28108 


.28404 


.28702 


.28998 


.29296 


.29502 


.29890 


17 


.29890 


.30188 


.30486 


.30782 


.31080 


.31378 


.31676 


18 


.31676 


.31976 


.32274 


.32572 


.32870 


.33170 


.33468 


19 


.33468 


.33768 


.34066 


•34366 


.34666 


•34966 


.35266 


20 


.35266 


.35566 


.35866 


.36166 


.36466 


.36768 


.37068 


21 


.37068 


.37368 


.37670 


•37972 


.38272 


.38574 


.38876 


22 


.38876 


.39178 


.39480 


.39782 


.40084 


.40388 


.40690 


^S 


.40690 


.40994 


.41296 


.41600 


.41904 


.42208 


.42512 


24 


.42512 


.42816 


.43120 


.43424 


.43728 


.44034 


.44338 


25 


.44338 


.44644 


.44950 


.45256 


.45562 


.45868 


.46174 


26 


.46174 


.46480 


.46786 


.47094 


.47400 


.47708 


.48016 


27 


.48016 


.48324 


.48632 


.48940 


.49248 


.49556 


.49866 


28 


.49866 


.50174 


.50484 


.50794 


.51004 


.51414 


.51724 


29 


.51724 


.52034 


•52344 


.52656 


.52966 


.53278 


.53590 


30- 


•53590 


•53902 


.54214 


.54526 


.54838 


.55152 


.55464 


31 


•55464 


.55778 


.56092 


.56406 


.56720 


.57034 


.57350 


32 


'5 7350 


.57664 


.57980 


.58294 


.58610 


.S8926 


.59242 


33 


,59242 


.59560 


.59876 


.60194 


.60510 


.60828 


.61146 


34 


.61146 


.61464 


.61782 


.62102 


.62420 


.62740 


.63060 


35 


63060 


.63380 


.63700 


.64020 


•64342 


.64662 


.64984 


36 


64984 


.65306 


.65628 


•65950 


.66272 


.66596 


.66920 


37 


66920 


.67242 


.67566 


.67890 


.68216 


.68540 


.68866 


38 


68866 


.69192 


.69516 


.69844 


.70170 


.70496 


.70824 


39 


70824 


.71152 


.71480 


.71808 


.72136 


.72464 


.72794 


40 


72794 


.73124 


.73454 


•73784 


.74114 


.74446 


•74776 


41 


.74776 


.75108 


.75440 


.75774 


.76106 


.76440 


.76772 


42 


.76772 


.77106 


.77442 


.77776 


.78110 


.78446 


.78782 


43 


.78782 


.79118 


•79454 


.79792 


.80130 


.80468 


.80806 


44 


.80806 


.81144 


.81482 


.81822 


.82162 


.82502 


.82842 


45 


.82842 


.83184 


.83526 


.83866 


.84210 


•84552 


.84894 



TABLE FOR COMPUTING TAPERS 



363 



Table for Computing Tapers 
The Tabulated Quantities = Twice the Tangent of Half the Angle. 



.84894 
.86962 
.89046 
.91146 
.93262 
•95396 
•97546 
.99716 
.01906 
.04114 
.06342 
.08592 
.10862 
•13154 
.15470 
.17810 
.20172 
.22560 
.24974 
.27414 
.29882 

•32378 
.34902 

•37456 
.40042 
.42658 
•45308 
•47992 
.50710 
•53466 
.56258 
.59088 
.61956 
.64868 
.67820 
.70816 
.73858 
.76946 
.80080 
.83266 
.86504 
.89792 

.93138 
.96540 



,85238 
.87308 

.89394 
.91496 
.93616 

.95752 
.97906 
.00080 
,02272 
,04484 
.06716 
.08968 
.11242 
.13538 
.15858 
.18202 
.20568 
.22960 
.25378 
.27824 
.30296 
.32796 
.35326 
•37984 
.40476 
.43098 

•45754 
.48442 
.51168 
•53928 
.56726 
•59562 
.62440 
•65356 
.68316 
.71320 
.74368 
.77464 
.80608 
.83802 
.87048 
.90346 
.93700 
.97112 



.85582 
.87656 
.89744 
.91848 
.93970 
.96110 
.98268 
.00444 
.02638 
.04854 
.07090 
.09346 
.11624 
.13924 
.16248 
.18594 
.20966 
.23362 

.25784 
.28234 
.30710 
.33216 
•35750 
.38314 
.40910 
•43538 
,46200 
.48894 
.51624 
•54392 
•57196 
.60040 
.62922 
.65846 
.68814 
.71824 
.74882 

.77984 
.81138 
.84340 
.87594 
.90902 
.94266 
.97686 



.85926 
.88002 
.90094 
.92202 
.94326 
.96468 
.98630 
.00808 
.03006 
.05226 
.07464 
.09724 
.12006 
.14310 
.16636 
.18988 
.21362 

•23764 
.26190 
.28644 
.31126 
•33636 
.36176 

.38744 
.41346 
.43980 
.46646 
.49348 
.52084 
.54856 
.57668 
.60516 
.63406 
•66338 
.69312 
.72332 
.75396 
.78506 
.81668 
.84878 
.88142 
.91458 
.94832 
.98262 



40' 



.86272 
.88350 
•90444 
.92554 
.94682 
.96828 
.98990 
.01174 
.03376 
.05596 
.07840 
.10102 
.12388 
.14696 
.17026 
.19382 
.21762 
.24166 
.26598 
.29056 
.31542 
.34056 
.36602 
•39176 
.41782 
.44422 

.47094 
.49800 

•52544 
.55322 
.58140 
.60996 
.63892 
.66830 
.69812 
.72836 
.75910 
.79030 
.82198 
.85418 
.88690 
.92016 
.95400 
.98840 



so- 



.86616 



.90794 
.92908 
•95038 
.97186 
■99354 
.01538 
.03744 
.05970 
.08214 
.10482 
.12770 
.15082 
.17418 
.19776 
.22160 
•24570 
.27006 
.29468 
.31960 
•34478 
.37028 
.39608 
.42220 
.44864 
•47542 
■50256 
.53004 
•55790 
.58612 
.61476 
.64380 
.67324 
•70314 
.73348 
.76428 

•79554 
.82732 
.85960 
.89240 
.92576 
.95968 
.99420 



•13154 
•15470 
.17810 
.20172 
.22560 

.24974 
.27414 
.29882 
•32378 
•34902 
•37456 
.40042 
.42658 
.45308 
.47992 
.50710 
.53466 
.56258 
.59088 
.61966 
.64868 
.67820 
.70816 
.73858 
.76946 
.80080 
.83266 
.86504 
.89792 
.93138 
.96540 
2 .00000 



Refer to page 364 for explanation of table. 



3^4 



TAPERS AND DOVETAILS 



TABLE FOR USE IN COMPUTING TAPERS 

In the table on pages 362 and 363 the quantities when expressed in 
inches represent the taper per inch corresponding to various angles 
advancing by 10 minutes from 10 minutes to go degrees. If an angle is 
given as, say, 27^ degrees and it is desired to find the corresponding taper 
in inches, the amount, 0.4894 may be taken directly from the table. 
This is the taper per inch of length measured as in Fig. 6, along the 
axis. The taper in inches per foot of length is found by multiplying 




Fig. 6. — Taper per Inch and Corresponding Angle 

the tabulated quantity by 12, and in this particular case would be 
0.4894" X 12 = 5.8728". Where the included angle is not found 
directly in the table, the taper per inch is found as follows: Assume 
that the angle in question is i2j degrees, then the nearest angles in the. 
table are 12° 10' and 12° 20', the respective quantities tabulated under 
these angles being 0.213 14 and 0.21 610. The difference between 
the two is 0.00296, and as 12^° is half way between 12° 10' and 
12° 20' one half of 0.00296, or 0.00148 is added to 0.213 14, giving 
0.21462" as the taper of a piece i inch in length and of an included 
angle of 121 degree. The taper per foot equals 0.21362" X 12 = 
2.5634". 



TABLE FOR DIMENSIONING DOVETAIL SLIDES AND GIBS 

The table on page 365 is figured for machine-tool work, so as to 
enable one to tell at a glance the amount to be added or subtracted in 
dimensioning dovetail slides and their gibs, for the usual angles up 
to 60 degrees. The column for 45-degree dovetails is omitted, as A 
and B would, of course, be alike for this angle. 

In the application of the table, assuming a base with even dimen- 
sions, as in the sketch Fig. 7, to obtain the dimensions x and y of 
the slide Fig. 8, allowing for the gib which may be assumed to be 
\ inch thick, the perpendicular depth of the dovetail being f inch, 
and the angle 60 degrees, look under column A for f inch and it 
will be found opposite this that B is 0.360 inch, which subtracted 
from 2 inches gives 1.640 inches, the dimension x. To find y first 
get the dimension 1.640 inches, then under the column for 6o-degree 
gibs (where C is J inch), D is found to be 0.289 inch, which is added 
to 1.640, giving 1,929 inches. 

In practice this dimension is usually made a little larger, say to 
the nearest 64th, to allow for fitting the gib. 



DIMENSIONING SLIDES AND GIBS 



365 



I 



%}i 



k_B-rf w-i 







Table for Dimensioning Dovetail Slides and Gibs 



B 


B 


B 


.018" 


.022" 


.027" 


.036" 


.044" 


•053" 


.072" 


.087" 


.105" 


.144" 


•175" 


.210" 


.216" 


.262" 


.314" 


.288'' 


.350" 


.420" 


.360'' 


•437" 


.525" 


.433" 


•525" 


.629" 


•505" 


.612" 


•734" 


.577" 


.700" 


-839" 


.649" 


.787" 


•944" 


.721" 


.875'' 


1.049" 


•794" 


.962" 


I-I53" 


.866" 


1.050" 


1.259" 


1. 010" 


1.225" 


1.469" 


1-154" 


1.400" 


1.677" 


1.298" 


1-575" 


1.888" 


1.442" 


1.750" 


2.097" 


1.588" 


1.925" 


2.307" 


1.732" 


2.100" 


2.517" 


2.020" 


2.450" 


2.937" 


2.308" 


2.800" 


3-356" 


2.598" 


3.150" 


3-776" 


2.885" 


3-501" 


4.195" 

1 



D 


D 


D 


.144" 


.152" 


.163" 


.216" 


.228" 


.244" 


.289" 


•305" 


.326" 


.361" 


.381" 


.407" 


•433" 


.457" 


.489" 


.577" 


.610" 


.652" 


.721" 


.762" 


.815" 


.866" 


•915" 


.979" 


1. 010" 


1.067" 


1. 142" 


1.154" 


1.220" 


1-305" 



.176" 
.264" 

.353" 

.442" 
•530^ 
.707" 
-883" 
1.060" 

1.237" 

1. 4 1 4" 




FIG. 8 



366 TAPERS AND DOVETAILS 

MEASURING EXTERNAL AND INTERNAL DOVETAILS 

The accompanymg table of constants is for use with the plug 
method of sizing dovetail gages, etc. The constants are calculated 
for the plugs and angles most in use; and to use them a knowledge 
of arithmetic is all that is required. The formulas by which they 
were obtained are added for the convenience of those who may have 
an unusual angle to make. 




Fig. 9. — External and Internal Dovetails 



As an example of the use of the table, suppose that Z, Fig. 9, is the 
dimension wanted, and that the dimension A and the angle a are 
known. A glance at the formulas above shows that Z = A — D. 
Then the constant D corresponding to the size of plug and the angle 
used is subtracted from A and the remainder equals Z. For instance, 
ii A = 4", the plug used = f, and the angle = 30 degrees, then 
Z = A-D=4''- 1.0245'' = 2.9755''. 



CONSTANTS FOR DOVETAILS 



^^1 



If A is not known but B and C are given, according to the formula 
below the table A = B -\- C F. Then if 5 = 3.134". C = J", 
and the angle is 30 degrees, as before, A = B -\- C F =^ 3-134" + 
{.'j^" X 1. 1547) = A"i whence Z can be found, as already shown. 

If the corners of the dovetail are flat, as shown in Fig. 9 at I and 
G, and the dimensions / and H and the angles are known, it will be 
found from the formulas below the table that A also = I + H F; 
so that if / = 3.8557", H = |", and the angle = ^o degrees, then 
A = I + HF = 3.8557" + (.125" X 1. 1547) = 4^^from which Z h 
found as before. 



Constants for Dovetails 



Plug 


60° 


55° 


50° 


45° 


40° 


35° 


30° 


r 


I 


I. 1830 
.3170 


1.0429 
.3233 


.9368 
.3410 


.8535 
•3536 


.7861 
.3666 


.7302 
,3802 


.6830 
•3943 


r 


D 

E 


1-7745 
•4755 


1.5643 
•4932 


1.4053 
.5115 


1.2803 

.5303 


I.1792 

•5499 


1.0954 
•5702 


1.0245 
•5915 


¥ 


D 
E 


2.3660 
.6340 


2.0858 
.6576 


1.8730 
.6820 


1.7070 
.7072 


1.5722 
•7332 


1.4604 
.7603 


1.3660 
.7886 


r 


D 

E 


3-5490 
.9510 


3.1286 
.9864 


2.S106 
1.0230 


2.5606 
1 .0606 


2.3584 
1.0998 


2.1903 
1. 1404 


2.0490 
1. 1830 




F 


3.4641 


2.8563 


2.3836 


2 


1.67S2 


1 .4004 


1.1547 



A = B + CF = I + HF 
B=A-CF = G-HF 



E = pfcot.9^±^Up 



D = P [cot. 
F = 2 tan a 



2 ; 

90 — a 



+ p 



368 



TAPERS AND DOVETAILS 



TOOL FOR LAYING OUT ANGLES ACCURATELY 

The bevel gage here shown is for laying out angles accurately. 
In using this gage set a vernier caliper or large "micrometer" to 
twice the sine of half the angle desired, multiplied by ten, add one 



m 



nm 



half inch and open the gage till it fits the vernier; this gives the angle 
within the limits of the measuring tool and the radius of the gage. 
The eighth-inch hole in the center is for a setting plug when it is 
desirable to lay out an angle from a given center. 

The table gives the measurements over the half disks requked for 
setting the arms of the gage to give any angle from i to 45 degrees, 
and also the setting for any number of holes in a circle from 3 to 22. 

Table For Setting Tool For Laying Out Angles 







Gage Setting For Even Degrees 








Measure- 


Angle 


Measure- 


Angle 


Measure- 


Angle 


Measure- 


Angle 


ment Over 


De- 


ment Over 


De- 


ment Over 


De- 


ment Over 


Degrees 


Disks 


grees 


Disks 


grees 


Disks 


grees 


Disks 


I 


0.6746 


12 


2.5906 


23 


4.4874 


34 


6.3474 


2 


0.8490 


13 


2.764 


24 


4.6582 


35 


6.5142 


? 


1.0236 


14 


2.9374 


25 


4.8288 


36 


6.6804 


4 


1. 1980 


15 


3.1106 


26 


4.9980 


37 


6.846 


5 


1-3724 


16 


3-2834 


27 


5.1690 


38 


7.0114 


6 


1.5468 


17 


3-4562 


28 


5-3384 


39 


7.1762 


7 


1. 7210 


18 


3.6286 


29 


5-5176 


40 


7-3404 


8 


1.8952 


19 


3.8010 


30 


5-6764 


41 


7-5042 


Q 


2.0692 


20 


3-Q730 


31 


5.8448 


42 


7.6674 


10 


2.2432 


21 


4.1448 


32 


6.0128 


43 


7.830 


II 


2.4170 


22 


4.3162 


33 


6.1804 


44 
45 


7.9922 
8.1536 



Gage Settings For Holes in a Circle 



No. of 

Holes in 

Circle 



Measure- 
ment Over 
Disks 



17.8206 
14.6422 
12.2558 
10.5 
9.1776 



No. of 
Holes 

in 
Circle 



Measure- 
ment Over 
Disks 



8.1536 
7-3404 
6.6802 
6.1346 
5-6762 



No. of 
Holes 

in 
Circle 



Measure- 
ment Over 
Disks 



5.2864 
4-9504 
4.6582 
4.4018 
4-1750 



No. of 
Holes 



Circle 



Measure- 
ment Over 
Disks 



3-9730 
3-7918 
3.6286 
3.4808 
3-3462 



SHOP AND DRAWING ROOM STANDARDS 

STANDARD JIG PARTS 
Drill Bushings 

When drilling and reaming operations are to be performed in 
the same jig, two slip bushings, one for the drill and the other for 
the reamer, should be used; if the jig is to be used for a large num- 
ber of parts, the hole for the bushings should in turn be bushed 
with a steel lining to prevent wearing. The soft cast-iron will wear 
rapidly if this is not done, and the jig will soon have to be rebored 
and rebushed. 




«-E»3 J^--G — *j 



'H-J 



Fig. I 
Loose Bushings 



4-P 




Fig. 2 
Fixed Bushings 



Loose Bushings 


Fixed Bushings 


A 


B 


c 


D 


E 


G 


H 


A 


B 


C 


No. 52 


I 


t\ 


i 


t'« 


T% 


tV 


52 


i 


tV 


No. 30 


1% 




i 




^ 


tV 


30 


16 




No. 12 


f 


f 


fV 


T¥ 






12 




iV 


i 


i 


H 


fV 


•1^ 


xf 


tV 


i 


V'« 


A 


A 


tk 


1 


^ 


f 


* 


tV 


tV 


i 


t 


4 


^ 


1 




1* 


+* 


tV 


^ 


^ 


^ 


H 


H 


f 


^ 




tV 


tV 


^ 


^ 




i 


i 


T6 


1* 


ItV 


tV 


i 


H 




t\ 


H 


i 


1^6 


I 


I* 


tV 


t^ 




f 


f 


i 


1* 


i 


ItV 




iV 


t 


1 


f 


ii 


}i 


I 


i 


li 


ij 




ii 


1^ 


H 


1 


itV 


I 


tHt 


li 


ItV 


tV 


• ^ 


I 


i 


if 


I* 


ItV 


rk 


Ifv 


i| 


tV 


H 


ItV 


i^ 


I 


li 


li 


t 


ItV 


i| 


tV 


^ 


li 


ii 


If 


ifV 


lA 


t 


li 


i+i 


tV 


+* 


ItV 


I 


I 


i^ 


li 


H 


i^ 


1 4 


tV 


I 


li 


I 



370 SHOP AND DRAWING ROOM STANDARDS 

Three different styles of bushings with their dimensions are shown 
in Figs. I, 2 and 3. These can be blanked out in quantities and 
finished to required sizes as needed, and should be made of tool 
steel. Allowances should be made in the blanks for grinding and 




A 


B 


c 


D 


E 


A 


B 


c 


D 


E 


^ 


tV 


H 


A 


A 


¥ 


11 


ItV 


1 


i| 


A- 


* 


f 


j\ 


^ 


i 


I 


li 


i 


ItV 


t 


TIT 


H 


^ 


H 


i* 


itV 


lA 


i 


li 


? 


k 


^ 


1 


1^ 


li 


i.i 


3^ 


if^ 


f 


H 


i 


J% 


t^ 


it 


lA 


ifV 


A 


It 


•ft 


f 


H 


i 


i 


I 


li 


iiV 


32 


It'6 


f 


i 


I 


i 


iiV 













Fig. 3. — Fixed Bushings 

lapping after hardening. Fig. i shows a slip bushing; Fig. 2 a 
stationary bushing, and Fig. 3 a stationary bushing where tools with 
stop collars are to be used. Such bushings as shown in Figs. 2 and 
3 are also used for linings for slip bushings. 





Fig. 4 
Collar-Head Jig Screws. 



Fig. 5 
Winged Jig Screws 



D 


Thrd. 


L 


T 


Ii 


m 


n 


a: 


s 


D 


Thrd. 


H 


L 


T 


\ 


20 


I 


f 


^ 


x\ 


i 


tV 


iH 


i 


20 


1 


I 


f 


TG 


t8 


I 


f 


Tft 


^ 


fV 




It'^ 


<^ 


18 


'? 


I 


f 


V 


t6 


i^ 


I 




^ 


^ 


f 


2 


5 


lO 


i 


li 


I 


tV 


14 


2 


i^ 


tV 


^ 


tV 


:| 


2^ 












i 


13 


2 


li 


1 


3^ i 


Hi 













JIG STRAP DIMENSIONS 



371 



Binding Screws 

Binding- screws should be made in various sizes and with threads 
to conform to the standard taps with which the shop is provided. 
When drills of a very large size are used, a screw wuth a square or 
hexagon head is best, as the work requires firm clamping. If the 
drills used are small, a winged screw will be sufficient and more con- 
venient, as it will require less time to manipulate. Some good screws 
for clamping straps are sho\^ai in Figs. 4 and 5. Of course the screws 
can be made of any length desired. 

When the work is to be held against the seat or a stop by means 
of a set-screw, such screws as shown in Figs. 6 and 7 will be found 
very useful. If, however, the work is very light, a wing screw can 
be used. 




W 



Xi 


< — 


-L— 






1 "■ 


' i ' ' 1 1 1 

1 ' 


il 






D 


Thrd. 


L 


h 


I 


C 


H 


s 


D 


Thrd. 


L 


W 


d 


i 


20 


I 


I 


i 


/^ 


i 


If 


1 


20 


4 


.040 


A 


^ 


18 


I 


T*k 


i 


■el 


fV 


ifV 


■f'-Q 


18 


I 


.057 


^% 


i 


16 


li 




h 


e? 


1 


i-i 


1 


16 


I 


tV 


i 


t'w 


14 


li 


t'-. 


r^ 


t\ 


1\ 


^n 


T^ 


14 


i^ 


/t 


* 


^ 


13 


I* 


h 


tV 


H 


i 


2 


i 


13 


li 


^v 


i 



Fig. 6 
Square- Head Jig Screws 



Fig. 7 
Headless Jig Screws 



Supporting Screws 

Figs. 8 and g show screws that are useful in supporting work against 
the thrust of drills when the work is of such a nature that it cannot be 
supported otherwise. 



Locking Screws 

A convenient hinge-cover locking screw is shown in Fig. 10. This 
screw, when used, should be adjusted so that only a quarter turn will 
be needed to clamp or release the cover, which should be slotted 
to admit the head of the screw. 

The different sizes of the styles of screws shown are not only used 
with drilling jigs, but are equally useful with other jigs and fixtures. 
These screws should be made of screw stock and case-hardened. 



372 SHOP AND DRAWING ROOM STANDARDS 





D 


Thrd. 


L 


h 


s 


H 


D 


Thrd. 


L 


h 


m 


S 


H 


T 


I 


20 


f 


f 


i^ 


^ 


i 


20 


f 


A 


^ 


li 


f 


^ 


1% 


18 


I 


i 


ih 


T^ 


tV 


18 


I 


^ 


3V 


iH 


I 


T^ 


i 


16 


I 


tV 


itV 




t 


16 


I 


1^ 


i 


iH 


I 


^ 



Fig. 8 
Nurled-Head Jig Screws 



Fig. 9 
Nurled-Head Jig Screws 



Strap Dimensions 

A convenient strap to use with these jigs is shown in Fig. 11. The 
straps should be made of bessemer steel and case-hardened after 
finishing. The slot G can be located in the proper position and made 
of such dimensions as to allow the strap lo be slipped back out of 
the way when work is being placed in and taken from the jig. 



111 



mil? 



Fig. 10. — Locking Jig Screws 




Fig. II. — Jig Straps 



D 


Thrd. 


H 


h 


L 


S 


T 


W 


A 


B 


C 


D 


E 


L 


^ 


18 


^ 


t 


I* 


2^ 


l^ 


itV 


h 


I 


if 


i 


^ 


2i 


^ 


16 




H 


if 


2A 


l^ 




^ 


I 


if 


i 


^ 


3 


■X 


14 


■^ 


f 


i| 


2f 


li 


I-^ 


1 


li 


2 


i 


T^ 


3* 


i 


13 


^ 


'i 


ll 


2I 


li 


lA 


1 


li 


2 


i^ 


A 


3^ 


*= 








SggCTgS 








t 




2 






4 



HANDLES AND KNOBS 



373 




|«_._g_.^ 




Hdi4^ 



o 
U 

c 



da 
en. 



w 



1^ 


cofOfOrOfOfOPOfOfOfOCO 


'Ho 


OOtHHWroTj-Tj-xo vo\o 




xxxxxxxxxxx 


1 


0000 ■^■^'^TfrJ-Tj-O OO 
1 1 1 1 1 1 1 1 1 1 1 


Oh 


„h^H^H^H^^^^^,,«^^^ 





-t^^^^:t^^^^^^ 


;^ 


'^l^iSH«"'*"*"*'°'-HHS'«^'o*=^H2 ■ 


hJ 


Ml(M,^r*^K5|00rHhOlOl00>O|00«H<H« " 1» 
M M 


U! 


M M M IH M 


1— » 




w 


MUM 





H M M M 


t* 


aj;2o^«i^H« ^ 


w 




Q 


'*°"^M'frt°rr'i??^ 


O 


hhmmmihi-imN 


M 


^%^^ ^ ^^r^^^^ 


<J 


"^ r*« O M C) 

fO "* ■* tOvO t^OO Ox M M M 



374 SHOP AND DRAWING ROOM STANDARDS 



Handles for Hand-Wheels 




No. 


A 


B 


C 


D 


E 


F 


G 


H 


J 


P.I. 


oo 


i+l 


it\ 


^1 


i 


t 


t\ 


f 


i 


^V 


28 


o 


2H 


lit 


-f 


M 




A 






^^« 


28 


i 


2it 


2 


-| 


M 


si 


* 


f 


t\ 


aV 


24 


2 


3t<t 


2^ 


I 


t'6 


i 




^ 


t\ 


sV 


24 


3 


3l* 


2H 


i^ 


i^ 


if 


1 


h 


f 


aV 


24 


4 


4i 


3i 


li 


i 


19 


f 


i 


t 


irV 


24 


5 


4t 


3tV 




A 


U 


tV 


i 


H 


aV 


20 


6 


5fV 


3t 


iyV 


t 


i 


i 


ii 


i 


aV 


16 



Knobs 







rt 



-t 



->E!< 






^J-; 



A 


B 


c 


D 


E 


F 


G 


H 


I 


J 


K 


tV 


I 


A 


M 


A 


tV 


i 


i 


H 


J% 




i 


ifV 


T6 


ii 


A 


t\ 


t\ 








4-. 


A 


lA 


j'^ 


ie 


* 


T^ 


A 


1 


It 6 




3 

CO 


* 


li 


t'« 


1 


* 


H 


^'. 


1^ 


if 







tV 


i^ 


t'« 


1 


* 


H 


^T 


tV 


if 


f 


"^ 


i 


If 


A 


ItV 


/^ 


1 


i 


^ 


if ■ 


3^ 


3 




♦ 


If 




i-V 


f*^ 


i 


i 


i 


ll 


tV 


f 


2i 


ii 


li 


T% 


W-. 


8^^ 


t\ 


2tV 


1 


3 


i^- 


2i 


li 


li 


tV 


itV 


TfV 


l\ 


2t'« 


* 


U 


^ 


2i 


ii 


li 


A 


itV 


3^ 


t\ 


2tV 


1 





BALL HANDLES 



375 



Ball Handles 
(Pratt & Whitney Co.) 



Center Ball 




A 


B 


C 


D 


E 


F 


G 


H 


I 


K 


L 


N 


3 


Ij6 


I 


f 


1 




3 


t\ 


h 


If 




t 


4 


I 35 


itV 


li 


I 


1* 


f 


H 


T% 


lit 


tV 


Ah 


l| 


I^ 


i 


Ifv 


li 


■X 


i 


f 


2^ 


t 


h 


5 


2tV 


lit 


l 


IT«B 


I^ 


h 


1^ 


i* 


2i^ 


M 


h 


5^ 


^-h 


%v 


1^ 


li 


ItV 


h 


^ 


H 


2f 


tV 


T% 


6 


2h 




I 


it\ 


ifV 


h 


it 


i 


3i 


i^ 


tV 


7 


2M 


2H 


ItV 


lA 




l\ 


I 


it 


3ii 


i 


f 


8 


3t6 


33^1 


li 


I^ 


iH 


A 


iiV 


i 


3t 


il 


1 



K--B-^, 



Binder Handles 




I 




1 


i 


c > 


i< ^D >i 



A 


B 


c 


D 


E 


F 


Dia. of Tap 


i^ 


f 

■ :: 


If 
If 


If 

2 
2f 


tV 


f 





376 SHOP AND DRAWING ROOM STANDARDS 



Single End Ball Handles. (Walcott & Wood) 




A 


B 


c 


D 


E 


F 


G 


H 


I 


3A 


4-\ 


i| 


1 


H 


i 


tV 


^ 


A 


3t 


4-1 


li 


1 


t* 


T> 


i 


I 


t\ 


4i 


5t 


if 


1 


i 


^ 


r*^ 


I 




4^^ 


6-V 


if 


I 


I 


H 




i^ 


1 


5l 


6- 


rf 


if 


li 


I 


-i 


f 


i^ 


f 


65 


7- 




2 


itV 


li 




f 


i^ 


tV 


6t 


7- 


-| 


2 


I^ 


lA 


f 


f 


i^ 


■J 


8 


9 


^i 


2i 


I^ 


if 


i 


i 


If 


tV 



Ball Lever Handles 



rr 




a 


B 


c 


D 


E 


F 


G 


H 


^ 


2| 


I 


If 


t 


H 


h 


if 


\ 


.S-f 


Ij 


If 


-* 


f 


A 


if 


1 


4- 


lA 


ilf 




1 


f 


If 


1 


5tV 


lA 


2j 


1 


1^ 


f 


If 


1 


(>h 


If 


2^ 


I 


1 


f 


2 




7H 


If 


2H 


I 


I 




Hi 


' 


8-1 


If 


4 


I 


iiV 


^ 


2i 



HOOK BOLTS 
Wing Nuts 



37r 




-^F 



^^ 



A 


B 


c 


D 


E 


F 


R 


T 


tI 


M 


3% 


^^ 


*i 


^% 


\ 


i 
A 


^TS 


f 


i 


tV 


1 


i 


i\ 


i 


I^ 


f 


i 


i 


1^ 


^ 


^ 


t\ 


if 


t* 


A 


h 


1 


^\ 


tV 


i 


ifl 


1 


^ 1 


t 


y'b 


^ 


i 


tV 


2A 


II^ 


i 


1 


H 


3\ 


i 


i 



Machine Handles 




A 


B 


c 


D 


E 


F 


G 


H 


H 




M 




it 


T^6 


li^ 


tV 


^ 


2| 




il 




if 


it 


fk 


2 


f 


H 


3^ 
si 


I 




tV 




i 


tV 


2^ 


f 


f 




lA 




it 


it 


t\ 


2H 


H 


H 


:ff 


li 




i 




i^ 


fV 


3i 


1 


II 




ItV 




iHr 


. *^ 


, t 


3i^ 


^ 


H 


si 


lA 




^ 




i 


A 


3l 


ii 


li 


sH 



378 SHOP AND DRAWING ROOM STANDARDS 
Thumb Nuts 



a 



'-^.^Ch^ 



D 


A 


B 


c 


MiU 


^ 




7 




i 




3\ 




A 




i 




I 




fk 




* 


t"^ 


^ 




li 




i 




3^'^ 




T^ 




'i 




li 




T^ 




3^2 


^^ 


t^H 




I^ 




i 




T^ 




i 




h 




2 




J% 




A 


i 


A 


f 


2i 


2i 


1 


H 


tV 


S^'j 


1 



Hook Bolts 




T 
L._i.. 



t 


C I— 


1 



Dia. of 


Thickness 


•Thickness 


Width 


Off Set 


Length 


Bolt 


of Head 


at End 


of Head 


of Head 


of Head 


A 


B 


C 


D 


E 


F 


1 


1^ 


A 


f 


tV 


H 


1 




i 


i 


i| 


iiV 


1 


-^ 


^ 




itV 


f 


if 


I 


J 


H 


IT% 


1 


-f 


1^ 


1 


H 


lit 


I 




§ 


I 


lA 


2tV 



COUNTERBORES WITH INSERTED PILOTS 379 

COUNTERBOEES WITH INSERTED PILOTS 



ji 


h __ 


T 


) 


— 1 


)- 




H 


1 


1 


ill 


f. 



-N 



i la 



I-- 




tA— 1 I- A ": 

ViXd I'Coonterbores f^ have 4 Flutes 
" " 6 '^ 



l"to 1}^" 



Diam. 










A 


K 


L 


M 


N 


I 


i^. 


\ 


4f 


t\ 


7 










16 










i 


" 




*' 




^\ 


iH 




2^V 


l\ 


5 










8 










ii 


" 




" 




^ 


" 




" 




\^ 


u 




" 




I 






'^ 




if 


" 




" 




I 


" 








It\ 


Hi 




2tl 




li 










lA 










;t 










Itv 










It 


<( 




(< 




n\ 


<< 




(< 




li 











From 

rV'toir 
in32nds. 



From 

rtofr 

in 32nds. 



From 
i" to x\f 
in32nds. 



Diam. 




















A 


B 


c 


D 


E 


F 


G 


H 


I 


J 


f 


A 


W 


A 


I 


ij 


3i 


A 


ItV 


i^ 


Ve 


" 


^A 




I3V 


ifV 


3l^ 




I^\ 






" 






ItV 


i« 


3i 




li 


(< 


T^ 


tV 


w 




li 


iH 


4i 




I-f^ 


i^ 


•| 


'' 


w 




I^ 


i^ 


4t'6 




It^6 


" 


H 


" 


li 




li 


lU 


4i 




l/^ 


" 


\ 


" 


M 




IT^« 


i^ 


4i* 




li 


<( 


W 


" 


H 




I* 


lit 


4ft 




I/^ 


(( 


\ 




2.1 




ItV 


2 


5i 




lA 


(( 


H 


" 


If 




li 


2tV 


5l 




iM 


« 


I 




it 




ife 


2i 


5t^ 




If 


<( 


lA 


h 


I 


3 


i^ 


2A 


5it 


16 


iH 


2f 


li 


*' 


ItV 




iH 


2i 


6 




ly'- 




itV 


" 


ItV 




i^ 


2t^« 


6i 




iM 


<( 


xi 


" 


li 




i|f 


2f 


6t^ 




i^ 


« 


itV 


" 


I^ 




i^ 


2tV 


6t 




i-H 


(( 


If 


" 


li 




lit 


2h 


6^ 




It\ 


«< 


lA 




I ¥ 




2 


2h 


7tV 




iM 


u 


li 




I 8 




2tV 


2« 


7-A 




it 


<t 



38o SHOP AND DRAWING ROOM STANDARDS 
Dimensions of Standard Plug and Ring Gages 




1 

i 

i 


I^^l 


j 1 




^EH ^F ^ 



Plug 


Ring 




^ 


"3 


-a 


1 


^ 
-§ 

rt 




*o 






1 




"o 


-S 


•o 


C 


5 




•s 


"o 


•s 


1^ 


^ 

M 


^ 


-t 


c/5^ 


i3 


.2 


(5 


.2 


5" 


.^ 


J 


r 


.2 
•o 




A 


B 


C 


D 


E 


F 


G 


H 


I 


i 


3^ 


_,_ 


I 


A 


2 


3A 




h 


A 




tV 


^ 


A 


• 2i 


3^ 


lA 


t\ 


1 


i 


I 


A 


2i 


3rk 


li 


^^ 


tV 


1 


i 


liV 


16 


2^ 


3f 


lA 


i 


^ 


tV 


A 


I* 




2^ 


4 


li 


^ 


T% 


■J^ 


A 


ItV 


f 


2| 


4fV 


li^ 


H 


f 


^ 


^ 


li 


1 


2f 


4t 


l^ 


U 


H 


t\ 


t 


II^ 


f 


2| 


4-% 


l^ 




f 


1 


li 


I^ 


tV 


3 


4tI 


If 


f 


if 


f 




ItV 


tV 


3i 


5 




n 


i 


-i 


f 


I^ 




3i 


5tV 


l| 


i 


H 


H 


4 


lA 


tV 


3i 


5i 


2 


H 




f 


1 


ll 


^ 


3i 


5l 


2* 




li 


f 


1 


If 


^ 


3i 


5^ 


2i 




li 


1 




if 


i 


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RADIAL BALL BEARINGS 



381 






«gogn|«>t-gH«»g«f«>^«h«2HH»15S r^-*0BgH^Ml2B(«Hn 



000 
^0 ir> M O CN vr> CM 
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M M 1-1 M ot c<o i/2\o 00 O M ■* t^ O o< lOOO M U100 M vr> fO 

MMHMHOIMOfOCOCO't-^lO 



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VO I^ l-H 00 roOO M t- OvO 00 VO O P< lOOO W VO Ov ro t^ m m 

M M CM M PO .^vo f-Ov« -^t^O rl-t~-0 >O00 <N t^ M ^O t^ 

MI-iHNNMfOrOtO'i-'^>'5 10\0 



>0000>^0>01>^>00»^00>J^OOOO'^000 
00 w '^cot^lOCS NvO tOMt-ol OvOvcOt^M M MVOO 
M M CM cocjiot^Ow -^t^O -^r^HnO O m O "O OvOc 

Hl-lMCM<NCMC0t0'*'*'O lOVO VO 



Owiov^OOOQOO 

MvOOO Ov-<tvOOO O rOO 
CM CM Ol CO ^O 00 1-1 ■* t^ 



10 O 'too -^OiOMOO 'ti-iO 
r« CM CO CO ■^ "^ lOvO O t>.00 0> 



H TJ-OO CM\C COOOOlOPOOt^lOCM Oi^-^M Or^TJ-MlC 

CO <N w M o O\00 O 10 T^ CO M O OiOO vO »o -^ 01 M O OiOO 
CO r^ w 10 0-0 ^CM OoOO TfM Ovt-^mcow or^iocMO 
Tt Tj- 10 VO vovo t^oo OiOOMCMCScort- loO \0 r^oo d 0> 

dddddddddOMMMMMMWMMMWMM 



O r^O •* CO O I^vO CO O t^ rt M c 
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CO 'to 00 q 'too M uoo>cot~.iH loovcMO q 'too tj-oo •* 

MMMMCMCMcicOCOCO't'^VOlO lOVO v© t^ ri t>.od CO d> 



Ov I-- 0>vO 00 00 00 



t^vO \0 vO to 1 



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CM cococococO'tt 



CM CO CO •<* •* to lovo <5 t^ r^oo 00 0> Oi O O M 






O iH CM CO •* lovo r^oo 0> O M 
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cococococococococococococococo 



CO 't >o\0 t^oo Ov O 



CO CO CO CO CO CO 




3S2 SHOP AND DRAWING ROOM STANDARD 



^"o.S 



N CO ro •* ■^ 10 vo 



cjffi^ 



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BALL THRUST COLLAR BEARINGS 



383 



1 . 


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384 SHOP AND DRAWING ROOM STANDARDS 




-o 


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10 


to vr> 


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COMBINED RADIAL AND THRUST BEARING 385 









to 


to 

















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to to 





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r^ 


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s:j S? 































































386 SHOP AND DRAWING ROOM STANDARDS 



.1 • 

s 
i 

> 


1 


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a 

3 
3 

1 


m 


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M COOO \0 t^ -T 
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c»0 ■* ^ vOvO O 


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cor^ w 


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OOO 


a.cgg 


if 


88 




- 


_c 


o^.q 


■* 'd- ^ 
q q q 


o=§^ 


^=§^ 


^qq 


M M M 


... 


M M 


6 

a" 






... 


... 


. CO CO 


CO CO CO 


CO CO CO 


COCO 








3 


.H 












■ '■ ? 


t^O CO 

rr t=o 
q M . 


vSg 
coup 
. . 


1 








: : : 




: : a, 

• • •* 


. 4oo o '^ 

iOto>0 VOVO 


-a 


q 


.s 


H 'toe 
ft"? 








p1 (^ fo 




t-i M M 


q. o 

M M 


1 


w <S ro 


Ti-u->r- 


^^r? 


'c?^_g^ 


M C0>0 

CO CO CO 


CO CO ^ 


coior^ 


?a 














O «^>o 

00 VO CO 
CO ^O 




B3 

OO H lO 
fi C^C^ 


O r-^ wco to 

t-O -t 00 M lO 
CO CO . HMO 

Ovcot- M LOOv 

CO 4 4 >A>oio 




coOvO COOO 
O 't ^ 00 00 
00 t^O lO '^ 
rfOO n- 00 ^ 
tir^od 00 dv 


a Q 

P 


_d 


s 

1 


lO t- <M 

CO CO -^ 




^cga 


322 


aja 


vBR^ 


?s? 


H 


1- 


3 


.s 


CO c^ O 


CO 't CO 


H OOO 

HCO T 

w CO lO 


t^ to Tt 

f^ OV M 


^C lO lO lO ^ •+ 
CO lO t^ O M CO 
fi <N cJ pi CO CO 


CO CO CO 


S5& 

4 4 


s 
s • 


2 m):? 


I^g^ 


O loO 

CO CO -^ 


too lo 


O ir>0 


lo O '-0 

t-ooao 


as8 


^2 

M H 


s5z 


M „ M 


III 


VO 1^00 

OOO 

CO 'O CO 


CO CO CO 


. CO '4- 

CO ^ CO 


CO lo CO 


CO coco 


M . 
N N 
CO CO 




'1" 





— / 






/^^ \ 


s 








^/' 


^1 












^ 

n 


:::z 


>-;c; 


^ 


>i__ 




"~<^' 




/> 






— H 






* 



















INTEGRAL RIGHT-ANGLED TRIANGLES 



3^7 



The erection of a perpendicular by the construction of a triangle 
whose sides are respectively 3, 4 and 5 units in length is a familiar 
and handy device. The following table gives a greater range of 
choice in the shape or proportions of the triangle employed. The 
table is a list of all integral, or whole-number, right-angled triangles 
the units of whose least sides do not exceed 20. 



Right 


Base 


Hypot- 
enuse 


Hight 


Base 


Hypot- 
enuse 


Hight 


Bnse 


Hypot- 
enuse 


3 


4 


5 


12 


16 


20 


17 


144 


195 


5 


12 


13 


12 


35 


37 


18 


24 


30 


6 


8 


10 


13 


84 


«> 


18 


80 


82 


7 


24 


25 


14 


48 


50 


19 


180 


181 


8 


15 


17 


15 


20 


25 


20 


21 


29 


9 


12 


15 


15 


36 


39 


20 


48 


52 


9 


40 


41 


15 


112 


113 


20 


99 


lOI 


ID 


24 


26 


16 


30 


34 








II 


60 


61 


16 


63 


65 









TABLE OF CHORDS 

To construct any angle from the table of chords, page 388 : Let the 
required angle be 36° 38'; the nearest angles in the table are 36° 30' and 
36° 40', and the chords are respectively 0.6263 and 0.6291, the differ- 
ence 0.0028 corresponding to an angular difference of 10'. To find 
the amount which must be added to 0.6263 (the chord corresponding 
to 36° 30') in order to obtain the chord for a 36° 38' arc, multiply 
0.0028 by Yo = 0.00224. 0.6263 + 0.00224 = 0.62854. Then, if the 
radius is i'^ and the angle 36° 38' the chord will be 0.62854*. 




In laying out an angle as in the accompanying illustration a base 
line A B can be drawn, say 10 inches long, then with a radius A B 
and center A, arc B C can be struck. Multiply chord 0.62854 inch 
by 10 giving 6.2854 inches^ as the radius 01 an arc to be struck from 
center B and cutting arc 5 C at C. Through point C draw a line 
A C and the angle B A C will equal 36° 38'. 

Where the angle required is in even degrees or sixths of degrees 
(as to', 20', etc.) the corresponding chord may be taken directly from 
the table. A 10 to i layout is particularly convenient as the multi- 
plication of the tabulated chords by 10 is readily performed mentally. 



SSS SHOP AND DRAWING "room STANDARDS 



Table of Chords 
the tabulated quantities = twice the sine of half the arc 



Deg. 


0' 


10' 


20' 


30' 


40' 


50' 


60' 


o 


.0000 


.0029 


.0058 


.0087 


.0116 


.0145 


.0174 


I 


.0174 


.0204 


•0233 


.0262 


.0291 


.0320 


.0349 


2 


•0349 


.0378 


.0407 


.0436 


.0465 


.0494 


•0523 


3 


.0523 


•0553 


.0582 


.0611 


.0640 


.0669 


.0698 


4 


.0698 


.0727 


.0756 


.0785 


.0814 


.0843 


.0872 


5 


.0872 


.0901 


.0930 


•0959 


.0988 


.1017 


.1047 


6 


.1047 


.1076 


.1105 


.1134 


.1163 


.1192 


.1221 


7 


.1221 


.1250 


.1279 


.1308 


■^337 


.1366 


.1395 


8 


.1395 


.1424 


•1453 


.1482 


.1511 


.1540 


.1569 


9 


.1569 


.1598 


.1627 


.1656 


.1685 


.1714 


-2 743 


lO 


.1743 


.1772 


.1801 


.1830 


.1859 


.1888 


.1917 


II 


.1917 


.1946 


.1975 


.2004 


•2033 


.2062 


.2090 


12 


.2090 


.2519 


.2148 


.2177 


.2206 


•2235 


.2264 


13 


.2264 


•2293 


.2322 


•2351 


.2380 


.2409 


•2437 


14 


•2437 


.2466 


.24Q5 


,2524 


•2553 


.2582 


.2610 


15 


.2610 


.2639 


.2668 


.2697 


.2726 


•2755 


•2783 


i6 


.2783 


.2812 


.2841 


.2870 


.2899 


.2927 


.2956 


17 


.2956 


.2985 


.3014 


.3042 


.3071 


.3100 


.3129 


i8 


.3129 


•3157 


.3186 


•3215 


•3243 


.3272 


•3301 


19 


•3301 


■3330 


.3358 


•3387 


.3416 


•3444 


•3473 


20 


•3473 


.3502 


•3530 


•3559 


•3587 


.3616 


•3645 


21 


•3645 


•3673 


.3702 


•3730 


•3759 


•3788 


•3816 


22 


.3816 


•3845 


.3873 


.3902 


•3930 


•3959 


•3987 


23 


.3987 


.4016 


.4044 


•4073 


.4101 


.4130 


.4158 


24 


.4158 


.4187 


.4215 


.4243 


.4272 


.4300 


.4329 


25 


4329 


•4357 


•4385 


•4414 


•4442 


•4471 


.4499 


26 


.4499 


•4527 


•4556 


.4584 


.4612 


.4641 


.4669 


27 


.4669 


.4697 


•4725 


•4754 


.4782 


.4810 


.4838 


28 


4838 


.4867 


.4895 


•4923 


•4951 


•4979 


.5008 


29 


.5008 


•5036 


.5064 


.5092 


.5120 


.5148 


•5176 


30 


•5176 


.5204 


•5232 


•5261 


•5289 


•5317 


•5345 


31 


•5345 


•5373 


.5401 


•5429 


•5457 


•5485 


•5513 


32 


•5513 


•5541 


•5569 


•5596 


.5624 


•5652 


.5680 


33 


.5680 


.5708 


•5736 


•5764 


•5792 


.5820 


•5847 


34 


•5847 


•5875 


•5903 


•5931 


•5959 


.5986 


.6014 


35 


.6014 


.6042 


.6069 


.6097 


.6125 


•6153 


.6180 


36 


.6180 


.6208 


.6236 


.6263 


.6291 


.6318 


.6346 


37 


.6346 


•6374 


.6401 


.6429 


.6456 


.6484 


.6511 


38 


.6511 


•6539 


.6566 


.6594 


.6621 


.6649 


.6676 


39 


.6676 


.6703 


.6731 


.6758 


.6786 


.6813 


.6840 


40 


.6840 


.6868 


.6895 


.6922 


.6950 


.6977 


.7004 


41 


.7004 


•7031 


•7059 


.7086 


•7113 


.7140 


.7167 


42 


.7167 


.7194 


.7222 


•7249 


.7276 


•7303 


•7330 


43 


•7330 


•7357 


.7384 


.7411 


•7438 


•7465 


.7492 


44 


.7492 


•7519 


•7546 


•7573 


.7600 


.7627 


•7654 


45 


.7654 


.7680 


.7707 


•7734 


.7761 


•7788 


•7815 



CHORDS 



389 



Table of Chords 
the tabulated quantities = twice the sine of half the arc 



Deg. 


0' 


10' 


20' 


30' 


40' 


50' 


60' 


46 


•7815 


.7841 


.7868 


-7895 


•7921 


.7948 


•7975 


47 


•7975 


.8001 


.8028 


•8055 


.8081 


.8108 


•8135 


48 


•8135 


.8161 


.8188 


.8214 


.8241 


.8267 


.8294 


49 


.8294 


.8320 


•8347 


•8373 


.8400 


.8426 


.8452 


50 


.8452 


.8479 


•8505 


-8531 


•8558 


.8584 


.8610 


51 


.8610 


.8636 


.8663 


.8689 


•8715 


.8741 


.8767 


52 


.8767 


•8793 


.8820 


.8846 


.8872 


.8898 


.8924 


53 


.8924 


.8950 


.8976 


.9002 


.9028 


•9054 


.9080 


54 


.9080 


.9106 


.9132 


-9157 


.9183 


.9209 


•9235 


55 


•9235 


.9261 


.9286 


.9312 


•9338 


•9364 


•9389 


56 


•9389 


•9415 


.9441 


.9466 


.9492 


.9518 


•9543 


57 


•9543 


•9569 


•9594 


.9620 


•9645 . 


.9671 


.9696 


58 


.9696 


.9722 


•9747 


.9772 


.9798 


•9823 


.9848 


59 


.9848 


.9874 


-9899 


•9924 


•9949 


•9975 


1 .0000 


60 


1 .0000 


1.0025 


1.0050 


1.0075 


1. 0100 


1.0126 


1.0151 


61 


1.0151 


1.0176 


1. 0201 


1.0226 


1. 025 1 


1.0276 


1. 0301 


62 


1. 0301 


1.0326 


1-0350 


1-0375 


1 .0400 


1.0425 


1.0450 


63 


1 .0450 


I -0475 


1.0500 


1.0524 


1-0550 


1-0574 


1.0598 


64 


1.0598 


1.0623 


1.0648 


1.0672 


1.0697 


1. 072 1 


1.0746 


65 


1.0746 


1.0770 


1-0795 


1. 08 19 


1 .0844 


1.0868 


1.0893 


66 


1.0893 


1.0917 


1. 094 1 


1.0966 


1 .0990 


1.1014 


1. 1039 


67 


I. 1039 


I. 1063 


1. 1087 


i.iiii 


I-II35 


1.1159 


1.1184 


68 


1.1184 


I. 1208 


1. 1232 


1. 1256 


1.1280 


1.1304 


1.1328 


69 


1.1328 


1-1352 


1. 1376 


1. 1400 


1. 1424 


1. 1448 


1.1471 


70 


1.1471 


1.1495 


1.1519 


1-1543 


I. 1567 


1.1590 


1.1614 


71 


1.1614. 


1. 1 638 


1.1661 


1. 1685 


1. 1708 


1. 1732 


1. 1756 


72 


1.1756' 


1. 1 780 


1. 1803 


1. 1826 


1. 1850 


1.1873 


1.1896 


73 


1.1896 


1. 1920 


1-1943 


I. 1966 


1.1990 


1.2013 


1.2036 


74 


1.2036 


1.2059 


1.2083 


I. 2106 


1.2129 


1.2152 


1.2175 


75 


1.2175 


1.2198 


1.2221 


1.2244 


1.2267 


1.2290 


1-2313 


76 


1^2313 


1.2336 


1.2360 


1.2382 


1.2405 


1.2427 


1.2450 


77 


1.2450 


1-2473 


1.2496 


T.2518 


1.2541 


1.2564 


1.2586 


78 


1.2586 


1.2609 


1.2631 


1.2654 


1.2677 


1.2699 


1.2721 


79 


1.2721 


1.2744 


1.2766 


1.2789 


1.2811 


1-2833 


1.2856 


80 


1.2856 


1.2878 


1.2900 


1.2922 


1.2945 


1.2967 


1.2989 


81 


1.2989 


1. 301 1 


1-3033 


1-3055 


1.3077 


1.3099 


1 .3 1 2 1 


82 


1.3121 


1-3143 


1-3165 


1.3187 


1.3209 


1-3231 


1-3252 


83 


1^3252 


1-3274 


1.3296 


1-3318 


1-3340 


1-3361 


1-3383 


84 


1-3383 


1.3404 


1.3426 


1-3447 


1.3469 


1.3490 


I-35I2 


h 


^•3512 


^-3533 


1-3555 


1-3576 


1-3597 


1.3619 


1.3640 


86 


1.3640 


1. 3661 


1.3682 


1-3704 


1-3725 


1-3746 


1-3767 


87 


1-3767 


1.3788 


1.3809 


1.3030 


I -385 1 


1.3872 


1^3893 


88 


^•3893 


1-3914 


1-3935 


1-3956 


1-3977 


1-3997 


1. 401 8 


89 


1.4018 


1.4039 


1 .4060 


1 .4080 


1.4101 


1. 41 2 1 


1. 4142 


•90 


1. 4142 















390 SHOP AND DRAWING ROOM STANDARDS 
Table for Spacing Holes in Circles 



r- 


Deg. of Arc 


„ 

•£5 
a 


■an 

1 


-a 

ro 

•£Q 

bO 
C 


1 
■5Q 


.3 


r 


3 


120 


.866 


1.732 


2.598 


3-464 


4.330 


5.196 


4 


90 


.707 


1.414 


2. 121 


2.828 


3-536 


4-243 


5 


72 


.5S8 


1. 176 


1.763 


2-351 


2.938 


3-527 


6 


60 


.500 


1. 000 


1.500 


2.000 


2.500 


3.000 


7 


5i°-25' 


.434 


.868 


1.302 


1.736 


2.170 


2.604 


8 


45 


.383 


.765 


1. 148 


1^531 


1-913 


2.296 


9 


40 


.342 


.684 


1.026 


1.368 


1. 710 


2,052 


lO 


36 


•309 


.618 


.927 


1.236 


1-545 


1.854 


II 


32°-43' 


.282 


.564 


.845 


1. 127 


1.409 


1. 69 1 


12 


30 


•259 


.518 


.776 


1-035 


1.294 


1-553 


13 


27°-4i' 


•239 


•479 


.718 


•958 


1. 197 


1.436 


14 


25°-42' 


.222 


•445 


.667 


.890 


1. 112 


1-334 


15 


24 


.208 


.416 


.624 


•832 


1.040 


1.247 


16 


220-30' 


•195 


•390 


•585 


.780 


-975 


1.171 


17 


2I°-Il' 


.184 


•367 


•551 


•735 


.918 


1. 102 


18 


20 


.174 


' -347 


•521 


•695 


.868 


1. 041 


19 


i8°-57' 


.164 


•329 


•493 


.658 


.822 


.987 


20 


18 


.156 


.318 


.469 


.626 


.782 


•937 


21 


17°- 8' 


.149 


.298 


•447 


•596 


.745 


•894 


22 


l6°-22' 


.142 


.286 


.427 


.569 


.712 


•855 


23 


i5°-39' 


.136 


•273 


.409 


•545 


.681 


.818 


24 


15 


.130 


.261 


•392 


.522 


.653 


.783 


25 


i4°-24' 


.125 


.251 


•375 


.501 


.627 


•752 


26 


i3°-5i' 


.120 


.241 


.361 


.482 


.602 


•723 


27 


I3°-20' 


.116 


.232 


.348 


.464 


•580 


•697 


28 


I2°-5l' 


.112 


.224 


•336 


•448 


.560 


.672 


29 


I2°-25' 


.108 


.216 


•324 


.432 


.540 


.648 


30 


12 


.104 


.209 


.314 


.418 


•522 


.627 


31 


ii°-37' 


.101 


.202 


■303 


. ^404 


•505 


.606 


32 


ii°-i5' 


.098 


.196 


•294 


•393 


.491 


.589 



SPACING HOLES IN CIRCLES 
T.A3LE FOR Spacing Holes in Circles 



391 



90 
72 
60 

45 
40 

36 

32°-43' 
30 

27°-4i 

25°-42 

24 

22°-30 
2I°-II 

20 

i8°-57 
18 
17°- 8 

l6°-2 2 

i5°-39 
IS 

i4°-24 
i3°-5i 

I3°-20 

I2°-5I 
I2°-2 5 
12 

ii°-37 
ii°-i5 



'0 

2 

to 

c 


L 


■BQ 

1 


1 

C 


1 


6.062 


6.928 


7.794 


8.660 


9.526 


4.950 


5.657 


6.364 


7.071 


7-778 


4.II5 


4.702 


5.290 


5.878 


6.465 


3.500 


4.000 


4.500 


5.000 


5-500 


3.037 


3-47I' 


3.905 


4.339 


4-773 


2.679 


3.061 


3.444 


3-827 


4.210 


2.394 


2.736 


3.078 


3.420 


3-762 


2.163 


2.472 


2.781 


3.090 


3-399 


1-973 


2.254 


2.536 


2.818 


3.100 


1.812 


2.069 


2.329 


2.588 


2.847 


1.676 


1.915 


2.154 


2-394 


2.633 


1.557 


1.779 


2.000 


2.224 


2.446 


1-455 


1.663 


1.871 


2.079 


2.287 


1.366 


1. 561 


1.756 


I -951 


2.146 


1.286 


1.469 


1-653 


1-837 


2.020 


1. 216 


1.389 


1.563 


1-737 


1.910 


1.151 


1.316 


1.480 


1.645 


1.809 


1.095 


1.251 


1.408 


1.564 


1.721 


1 .043 


1. 192 


1.341 


1.489 


1.639 


.996 


I-I39 


1.281 


1.423 


1.566 


•954 


1.092 


1.227 


1-363 


1.499 


.914 


1.044 


I.I75 


1-305 


1.436 


.877 


1.003 


1.128 


1-253 


1-379 


.843 


•963 


1.084 


1.204 


1-325 


.813 


•929 


1.045 


1. 161 


1.277 


.784 


.896 


1.008 


1. 121 


1-233 


.756 


.864 


.972 


1.080 


1. 188 


.732 


.836 


.941 


1.045 


1. 150 


.707 


.808 


.910 


1. 01 1 


1. 112 


.687 


.785 


.883 


.982 


1.080 



392 SHOP AND DRAWING ROOM STANDARDS 

TABLE FOR SPACING HOLES IN CIRCLES 

The table on pages 390 and 391 will be found of service when it 
is desired to space any number of holes up to and including 32, in a 
circle. The number of divisions or holes desired will be found in 
the first column, the corresponding angle included at the center 
being given as a convenience in the second column. The remaining 
column heads cover various diameters of circles from i to 12 inches, 
and under these different heads and opposite the required number of 
holes will be found the lengths of chords or distances between hole 
centers for the given circle diameter. 

Thus, if it is required to space off 18 holes in an 8-inch circle, by 
following down the first column until 18 is reached and then reading 
directly to the right, in the column headed "Length of Chord- 
Dia. 8," will be found the distance 1.389 as the chord length for that 
number of divisions and diameter of circle. Or, suppose a circle of 
12 inches diameter is to be spaced off for a series of 27 holes to be 
drilled at equal distances apart: Opposite 27 found in the first 
column, and under the heading, "Dia, 12," will be found the chord 
1.393 as the length to which the dividers may be set directly for lay- 
ing off the series of holes. 

If it is desired to lay off a scries of holes in a circle of some diam- 
eter not given in the table, say 10 holes in an iij-inch circle, sub- 
tract the chord for 10 holes in an ii-inch circle, or, 3.399 from the 
chord in the "Dia. 12" column, or 3.708, and add half the difference 
(.154) to 3.399, giving 3.553 as the chord or center distance between 
holes. Or, if 24 holes are to be equally spaced in a 20-inch circle, 
all that is necessary in order to find the chord, or center distance, is 
to find opposite 24, and in the column headed, "Dia. 10," the 
quantity 1.305 and multiply this by 2, giving a length of 2.610 inches 
as the center distance. 



TABLE OF SIDES, ANGLES AND SINES 

The table on pages 393 to 397 is carried out for a much higher 
number of sides or spaces than are included in the preceding table 
and will be found useful in many cases not covered by that table. 
It was originally computed for finding the thicknesses of commutator 
bars and also for calculating the chord for spacing slots in armature 
punchings. In using this table the diameter of the circle is, of 
course, multij)lied by the sine opposite the desired number of holes 
or sides. 

Assuming for illustration that a series of 51 holes are to be equally 
spaced about a circle having a diameter of 17 inches, opposite 51 in 
the column headed "No. of Sides," find the quantity .06156 in. the 
column headed "Sine," and multiply this quantity by 17. The 
product 1.0456 is the length of the chord or the required distance 
between centers of the holes for this circle. Or, if 40 equidistant 
points are to be spaced about a circle 16 inches diameter, opposite 
the number of sides, 40, will be found the quantity .078459 which 
multiplied by 16 gives 1.255 ^ch as the distance between centers. 



TABLE OF SIDES, ANGLES AND SINES 393 

MULTIPLY DIAMETER BY SINE TO GET LENGTH OF SIDE 

(Angle given is half of angle subtended at center) 



No. 


Angle 


Sine 


No. 


Angle 


Sine 


Sides 


Deg. Min. Sec. 


Sides 


Deg. Min. Sec. 


• 3 


60 


.8660254 • 


52 


3-27-41.53 


.060.3784 


4 


45 


.7071067 


53 


3-23-46.41 


.0592405 


5 


36 


-5877852 


54 


3-20 


.0581448 


6 


30 


.5000000 


55 


3-1 6-2 1. 8 1 


.0570887 


7 


25-42-51-42 


.4338828 


56 


3-12-51.42 


.0560704 


8 


22-30 


.3826834 


57 


3- 9-28.42 


.0550877 


9 


20- 


.3420201 


58 


3- 6-1 2. 4 1 


.0541388 


lO 


18- 


.3090170 


59 


3- 3- 3-05 


.0532221 


II 


16-21-49.09 


.2817325 


60 


3- 


.0523360 


12 


15- 


.2588190 


61 


2-57- 2.95 


.0514787 


13 


13-50-46.15 


-2393157 


62 


2-5 4-1 1. 6 1 


.0506491 


14 


12-51-25.71 


.2225208 


63 


2-51-25.71 


.0498458 


15 


12 


.2079116 


64 


2-48- 45 


.0490676 


i6 


11-15 


.1950903 


65 


2-46- 9.23 


•0483133 


17 


10-35-17-64 


.1837495 


66 


2-43-38-18 


.0475819 


i8 


10- 


.1736481 


67 


2-41-11.64 


.0468722 


19 


9-28-25.26 


•1645945 


68 


2-38-49.41 


.0461834 


20 


9- 


-1564344 


69 


2-36-31-30 


•0455145 


21 


8-34-1 7.14 


.1490422 


70 


2-34-1 7. T4 


.0448648 


22 


8-10-54.54 


.1423148 


71 


2-32- 6.76 


-0442333 


23 


7-49-33.91 


.1361666 


72 


2-30 


.0436194 


24 


7-30- 


.1305262 


73 


2-27-56.71 


.04302:^2 


^^ 


7-12- 


•1253332 


74 


2^25-56.75 


.0424411 


26 


6-55-23-07 


.1205366 


75 


2-24- 


.041875,- 


27 


6-40 


.1160929 


76 


2-22- 6.31 


.0413249 


28 


6-25-42.85 


.1119644 


77 


2-20-15.58 


.0407885 


29 


6-12-24.82 


.1081189 


78 


2-18-27.69 


.0402659 


30 


6- 


.1045284 


79 


2-16-42.53 


•0397565 


31 


5-48-23.22 


.1011683 


80 


2-15- 


.0392598 


32 


5-37-30 


.0980171 


81 


2-13-20 


•0387753 


33 


5-27-16.36 


.0950560 


82 


2-1 1-42 .45 


.0383027 


34 


5-17-38.82 


.0922683 


83 


2-10- 7.22 


.0378414 


35 


5- 8-34.28 


.0896392 


84 


2- 8-34.28 


.0373911 


36 


5- 


•0871557 


85 


2- 7- 3-54 


.0369515 


■ 37 


4-51-53-51 


.0848058 


86 


2- 5-34.88 


.0365220 


38 


4-44-12.63 


.0825793 


87 


2- 4- 8.27 


.0361023 


39 


4-36-55-38 


.0804665 


88 


2- 2-43.63 


.0356923 


40 


4-30- 


.0784591 


89 


2- 1-20.89 


.0352914 


41 


4-23-24.87 


.0765492 


90 


2- 


.0348995 


42 


4-17- 8.57 


.0747301 


91 


1-58-40.87 


.0345160 


43 


4-1 1- 9.76 


.0729952 


92 


1-57-23.47 


.0341410 


44 


4- 5-27-27 


•0713391 


93 


1-56- 7.74 


•0337741 


45 


4 


.0697565 


94 


1-54-53 -61 


•0334149 


46 


3-54-46.95 


.0682423 


95 


1-53-41.05 


•0330633 


47 


3-49-47-23 


.0667926 


96 


1-52-30. 


.0327190 


48 


3-45- 


.0654031 


97 


1-51-20.41 


.0323818 


49 


3-40-24.49 


.0640702 


98 


1-5 0-12. 24 


•0320515 


50 


3-36- 


.0627905 


99 


1-49- 5-45 


.0317279 


51 


3-31-45-88 


.0615609 


1 100 


1-48- 


.0314107 



394 



TABLE OF SIDES, ANGLES AND SINES 





MULTIPLY 


DIAMETER BY SINE TO GET LENGTH OF SIDE 




(Angle 


given is half of angle subtended at center) 


No. 
Sides 


Angle 
Deg. Min. Sec. 


Sine 


No. 

Sides 


Angle 
Deg. Min. Sec. 


Sine 


lOI 


^.-46-5 5 -84 


.0310998 


151 


I-II-31.39 


.0208037 


102 


1-45-52-94 


.0307950 


152 


I-ll- 3.15 


.0206668 


103 


1-44-5 1. 2 6 


.0304961 


153 


I-IO-35.29 


.0205318 


104 


1-43-50.76 


.0302029 


154 


I-IO- 7.79 


.0203985 


105 


1-42-5 1. 42 


.0299154 


155 


I- 9-40.64 


.0202669 


106 


1-41-53-20 


.0296332 


156 


I- 9-13.84 


.0201370 


107 


1-40-56.07 


.0293564 


157 


I- 8-47-38 


.0200087 


108 


1-40- 


.0290847 


158 


I- 8-21.26 


.0198821 


109 


1-39- 4.95 


.0288179 


159 


I- 7-55-47 


.0197571 


110 


I-38-I0.90 


.0285560 


160 


I- 7-30 


.0196336 


III 


1-37-17-83 


.0282488 


161 


I- 7- 4-84 


.0195117 


112 


1-36-25. 71 


.0280462 


162 


I- 6-40 


.0193913 


113 


1-35-34.5 1 


.0277981 


163 


I- 6-15.46 


.6192723 


114 


1-34-44-21 


.0275543 


164 


I- 5-51-21 


.0191548 


115 


1-33-54-78 


.0273147 


165 


I- 5-27.27 


.0190387 


116 


'^-33- 6.20 


.0270793 


166 


I- 5- 3-61 


.0189241 


117 


1-32-18.46 


.0268479 


167 


I- 4-40.23 


.0188107 


118 


1-3 1-3 1. 5 2 


.0266204 


168 


I- 4-17-14 


.OT86988 


119 


1-30-45.38 


.0263968 


169 


I- 3-54.31 


.0185881 


120 


1-30- 


.0261769 


170 


I- 3-31-76 


.0184788 


121 


1-29-15-37 


.0259606 


171 


I- 3- 9-47 


.0183708 


122 


1-28-3 1. 47 


.0257478 


172 


I- 2-47.44 


.0182640 


123 


1-27-48.29 


.0255386 


173 


I— 2-25.66 


.0181584 


124 


1-27- 5.80 


.0253326 


174 


I- 2- 4.13 


.0180541 


125 


1-26-24 


.0251300 


175 


I- 1-42.85 


.0179509 


126 


1-25-42.85 


.0249306 


176 


I- 1-21.81 


.0178489 


127 


1-25- 2.36 


.0247344 


177 


I- I- 1. 01 


.0177481 


128 


1-24-22.50 


.0245412 


178 


I- 0-40.44 


.0176484 


129 


1-23-43.25 


.0243509 


179 


I- 0-20.11 


-0175498 


130 


1-23- 4.61 


.0241637 


180 


I- - 


.0174524 


131 


1-22-26.56 


.0239793 


181 


-59-40.11 


-0173559 


132 


I -2 1 -49 .09 


.0237976 


182 


-59-20.43 


.0172605 


^33 


1-21-12.18 


.0236188 


,183 


-59- 0.98 


.0171663 


134 


1-20-35.82 


.0234425 


184 


-58-41.73 


.0170730 


135 


1-20- 


.0232689 


185 


-58-22.70 


.0169807 


136 


1-19-24.70 


.0230978 


186 


-58- 3-87 


.0168894 


137 


1-18-49.92 


.0229292 


187 


-57-45.24 


.0167991 


138 


1-18-15.65 


.0227631 


188 


-57-26.30 


.0167097 


139 


1-17-41.87 


.0225994 


189 


-57- 8.57 


.0166214 


140 


1-17- 8.57 


.0224380 


190 


-56-50.52 


.0165339 


141 


1-16-35.74 


.0222789 


191 


-56-32.67 


.0164473 


142 


1-16- 3.38 


.0221220 


192 


-56-15 


.0163617 


143 


1-15-31.46 


.0219673 


193 


-55-57-51 


.0162769 


144 


1-15- 


.0218148 


194 


-55-40.20 


.0161930 


145 


1-14-28.96 


.0216644 


195 


-55-23-07 


.0161100 


146 


1-13-58.35 


.0215160 


196 


-55- 6.12 


.0160278 


147 


1-13-28.16 


.0213697 


197 


-54-49-34 


.0159464 


148 


1-12-58.37 


.0212253 


198 


-54-32.72 


.0158659 


149 


i-i 2-28.99 


.0210829 


199 


-54-16.28 


.0157862 


150 


1-12- 


.0209424 


200 


-54- 


.0157073 



TABLE OF SIDES, ANGLES AND SINES 395 

MULTIPLY DIAMETER BY SINE TO GET LENGTH OF SIDE 

(Angle given is half of angle subtended at center) 



No. 

Sides 


Angle 
Min. Sec. 


Sine 


No. 
Sides 


Angle 
Min. Sec. 


Sine 


20I 


53-43-88 


.0156244 


251 


43- 1-67 


.0125160 


202 


53-27-92 


•0155518 


252 


42-51.43 


.0124663 


203 


53-12.12 


•0154752 


253 


42-41.26 


.0124171 


204 


52-56.47 


-0153993 


254 


42-31.18 


.0123682 


205 


52-40.97 


.0153242 


255 


42-21.18 


.0123197 


206 


52-25-63 


.0152498 


256 


42-11.25 


.0122715 


207 


52-10.44 


.0151764 


257 


42- 1.40 


.0122238 


208 


51-55-38 


•0151033 


258 


41-51.63 


.0121764 


209 


51-40.48 


.0150310 


259 


41-41.93 


.0121294 


210 


51-25-71 


-0149595 


260 


41-32.31 


.0120827 


211 


51-11.09 


.01488S6 


261 


41-22.76 


.0120364 


212 


50-56.60 


.0148183 


262 


41-13.28 


•01 1990s 


213 


50-42.25 


.0147487 


263 


41- 3-88 


.0119449 


214 


50-28.04 


.0146798 


264 


40-54.54 


.0118997 


215 


50-13.96 


.0146115 


265 


40-45.28 


.0118548 


216 


50- 


.0145439 


266 


40-36.09 


.0118102 


217 


49-46.17 


.0144769 


267 


40-26.96 


.0117660 


218 


49-32.48 


.0144104 


268 


40-17.91 


.0117221 


219 


49-18.91 


.0143446 


269 


40- 8.93 


.0116786 


220 


49- 5.46 


.0142794 


270 


40- 


.0116353 


221 


48-52.13 


.0142148 


271 


39-51-14 


.0115923 


222 


48-38.92 


.0141508 


272 


39-42.35 


.0115497 


223 


48-25.83 


.0140874 


273 


39-33-63 


.0115074 


224 


48-12.86 


.0140245 


274 


39-24.96 


.0114654 


225 


48- 


.0139622 


275 


39-16.36 


.0114237 


226 


47-47.26 


.0139004 


276 


39- 7-83 


.0113823 


227 


47-34.63 


.0138392 


277 


38-59-35 


.0113412 


228 


47-22.11 


•0137785 


278 


38-50.94 


.0113004 


229 


47- 9-69 


.0137183 


279 


38-42.58 


.0112599 


230 


46-57-39 


.0136587 


280 


38-34.28 


.0112197 


231 


46-45.19 


•0135995 


281 


38-26.05 


.0111798 


232 


46-33.10 


.0135409 


282 


38-17.87 


.0111401 


233 


46-2 1. 1 1 


.0134828 


283 


38- 9-75 


.0111008 • 


234 


46- 9-23 


.0134252 


284 


38- 1.69 


.0110617 


235 


45-57-45 


.0133681 


285 


37-53-68 


.0110229 


236 


45-45-76 


•0133115 


286 


17-45-73 


.0109844 


237 


45-34.18 


•0132553 


287 


37-37-84 


.0109461 


238 


45-22.69 


.0131996 


288 


37-30 


.0109081 


239 


45-11.29 


.0131444 


289 


37-22.21 


.0108704 


240 


45- 


.0130896 


290 


37-14.48 


^0108329 


241 


44-48.80 


•0130353 


291 


37- 6.80 


•0107957 


242 


44-37.68 


.0129814 


292 


36-59.18 


.0107587 


243 


44-26.67 


.0129280 


293 


36-5 1 .60 


.0107220 


244 


44-15-74 


.0128750 


294 


36-44-08 


.0106855 


245 


44- 4.90 


.0128225 


295 


36-36.61 


.0106493 


246 


43-54.15 


.0127704 


296 


36-29.19 


.0x06133 


247 


43-43-48 


.0127187 


297 


36-21.82 


.0105776 


248 


43-32.40 


.0126674 


298 


36-14.50 


.0105421 


249 


43-22.41 


.0126165 


299 


36- 7.22 


.0105068 


250 


43-12 


.0125661 


300 


36- 


.0104718 



39^ TABLE OF SIDES, ANGLES AND SINES 

MULTIPLY DIAMETER BY SINE TO GET LENGTH OF SIDE 

(Angle given is half of angle subtended at center) 



No. 
Sides 


Angle 
Min. Sec. 


Sine 


No.' 
Sides 


Angle 
Min. Sec. 


Sine 


301 


35-52.82 


.0104370 


351 


30-46.15 


.0089502 


302 


35-45-69 


. .0104024 


352 


30-40.91 


.0089248 


303 


35-38.61 


.0103681 


353 


30-35-69 


.0088996 


304 


35-31.58 


.0103340 


354 


30-30.51 


.0088744 


305 


35-24.59 


.0103001 


355 


30-25-35 


.0088494 


306 


35-17.65 


.0102665 


356 


30-20.22 


.0088245 


307 


35-10.75 


.0102330 


357 


30-15.12 


.0087998 


308 


35- 3-90 


.0101998 


358 


30-10.05 


.0087753 


309 


34-57.09 


.0101668 


359 


30- 5-01 


.0087508 


310 


34-50.32 


.0101340 


360 


30- 


.0087265 


311 


34-43.60 


.0101014 


361 


29-55.01 


.0087023 


312 


34-36.92 


.0100690 


362 


29-50.05 


.0086783 


313 


34-30.29 


.0100368 


363 


29-45.12 


.0086544 


314 


34-23.69 


.0100049 


364 


29-40.22 


.0086306 


315 


34-17.14 


.0099731 


365 


29-35-34 


.0086070 


316 


34-TO.63 


.0099415 


366 


29-30.49 


.0085835 


317 


34- 4.16 


.0099102 


367 


29-25.67 


.0085601 


318 


33-57-74 


.0098791 


368 


29-20.87 


.0085368 


319 


33-51-35 


.0098482 


369 


29-16.10 


.0085137 


320 


33-45 


.0098174 


370 


29-11-35 


.0084907 


321 


33-38.69 


.0097868 


371 


29- 6.63 


.0084678 


322 


33-32.42 


.0097564 


372 


29- 1.94 


.0084451 


323 


33-26.19 


.0097261 


373 


28-57.27 


.0084224 


324 


33-20 


.0096961 


374 


28-52.62 


.0083999 


325 


33-13-85 


.0096663 


375 


28-48 


.0083775 


326 


33- 7-73 


• .0096367 


376 


28-43.40 


.0083552. 


327 


33- 1-65 


.0096072 


377 


28-38.83 


•0083331 


328 


32-55-61 


.0095779 


378 


28-34.28 


.0083110 


329 


32-49.60 


.0095488 


379 


28-29.76 


.0082891 


330 


32-43.64 


.0095198 


380 


28-25.26 


.0082673 


33^ 


32-37-70 


.0094911 


381 


28-20.78 


.0082456 


332 


32-31.81 


.0094625 


382 


28-16.33 


.0082240 


333 


32-25.95 


.0094341 


383 


28-1 1. 9 1 


.0082025 


334 


32-20.12 


.0094059 


384 


28- 7.50 


.0081812 


335 


32-14.33 


.0093778 


385 


28- 3.12 


.0081599 


336 


32- 8.57 


.0093499 


386 


27-58.76 


.0081387 


337 


32- 2.85 


.0093221 . 


387 


27-54.42 


.0081177 


338 


31-57-16 


.0092945 


388 


27-50.10 


.0080968 


339 


31-51-50 


.0092671 


389 


27-45-81 


.0080760 


340 


31-45.88 


.0092398 


390 


27-41.54 


.0080553 


341 


31-40.29 


.0092127 


391 


27-37.29 


.0080347 


342 


31-34.74 


.0091858 


392 


27-33.06 


.0080142 


343 


31-29.21 


.0091590 


393 


27-28.85 


.0079938 


344 


31-23.72 


.0091324 


394 


27-24.67 


•0079735 


345 


31-18.26 


.0091059 


395 


27-20.51 


•0079533 


346 


31-12.83 


.0090796 


396 


27-16.36 


.0079332 • 


347 


31- 7-44 


•0090534 


397 


27-12.24 


.0079132 


348 


31- 2.07 


.0090274 


398 


27- 8.14 


•0078934 


349 


30-56.73 


.0090016 


399 


27- 4.06 


•0078736 


350 


30-51-43 


.0089758 


400 


27- 


.0078534 



TABLE OF SIDES, ANGLES AND SINES 

MULTIPLY DIAMETER BY SINE TO GET LENGTH OF SIDE 

(Angle given is half of angle subtended at center) 



397 



No. 


Angle 


Sine 


No. 


Angle 


Sine 


Sides 


Min. Sec. 


Sides 
451 


Min. Sec. 


401 


26-55.96 


.0078343 


23-56.81 


.0069658 


402 


26-51.94 


.0078148 


452 


23-53.63 


.0069504 


403 


26-47.94 


.0077954 


453 


23-50.46 


•0069351 


404 


26-43.96 


.0077761 


454 


23-47-31 


.0069198 


405 


26-40 


.0077569 


455 


23-44.17 


.0069046 


406 


26-36.06 


.0077378 


456 


23-41.05 


.0068894 


407 


26-32.14 


.0077188 


457 


23-37-94 


.0068744 


408 


26-28.23 


.0076999 


458 


23-34.84 


.0068594 


409 


26-24.35 


.0076811 


459 


23-31.76 


.0068444 


410 


26-20.49 


.0076623 


460 


23-28.69 


.0068295 


411 


26-16.64 


.0076437 


461 


23-25.64 


.0068147 


412 


26-12.82 


.0076251 


462 


23-22.60 


.0067999 


413 


26- 9.01 


.0076067 


463 


23-19-57 


.0067852 


414 


26- 5.22 


.0075883 


464 


23-16.55 


.0067706 ■ 


415 


26- 1.45 


.0075700 


465 


23-1.3-55 


.0067561 


416 


25-57-70 


.0075518 


466 


23-10.56 


.0067416 


417 


25-53-96 


•0075337 


467 


23- 7-58 


.0067272 


418 


25-50.24 


•0075157 


468 


23- 4.61 


.0067128 


419 


25-46.54 


•0074977 


469 


23- 1.66 


.0066985 


420 


25-42.86 


.0074799 


470 


22-58.72 


.0066842 


421 


25-39-19 


.0074621 


471 


22-55.79 


.0066700 


422 


25-35-54 


.0074444 


472 


22-52.88 


.0066559 


423 


25-31-91 


.0074268 


473 


22-49.98 


.0066418 


424 


25-28.30 


•0074093 


474 


22-47.09 


.0066278 


425 


25-24.70 


.0073919 


475 


22-44.21 


.0066138 


426 


25-21.12 


•0073745 


476 


22-41.34 


•0065999 


427 


25-17-56 


•0073573 


477 


22-38.49 


.0065861 


428 


25-14.02 


.0073401 


478 


22-35.65 


.0065723 


429 


25-10.49 


.0073230 


479 


22-32.82 


.0065585 


430 


25- 6.98 


•0073059 


480 


22-30 


.0065449 


431 


25- 3-48 


.0072890 


481 


22-27.20 


.0065313 


432 


25- 


.0072721 


482 


22-24.40 


.0065178 


433 


24-56.54 


•0072553 


483 


22-21.61 


.0065043 


434 


24-53-09 


.0072386 


484 


22-18.84 


.0064909 


435 


24-49.66 


.0072220 


485 


22-16.08 


.0064775 


436 


24-46.24 


.0072054 


486 


22-13.33 


.0064641 


437 


24-42.84 


.0071889 


487 


22-10.59 


.0064509 


438 


24-39-45 


.0071725 


488 


22- 7.87 


.0064377 


439 


24-36.08 


.0071562. 


489 


22- 5.16 


.0064245 


440 


24-32.73 


.0071399 


490 


2 2- 2.45 


.0064114 


441 


24-29.39 


.0071237 


491 


21-59-75 


.0063983 


442 


24-26.06 


.0071076 


492 


21-57.07 


.0063853 


443 


24-22.75 


.0070916 


493 


21-54.40 


.0063723 


444 


24-19.46 


.0070756 


494 


21-51.74 


.0063594 


445 


24-16.18 


-0070597 


495 


21-49.09 


.0063466 


446 


24-12.91 


.0070439 


496 


21-46.45 


.0063338 


447 


24- 9.66 


.0070281 


497 


21-43.82 


.0063211 


448 


24- 6.43 


.0070124 


498 


21-41.20 


.0063084 


449 


24- 3.21 


.0069968 


499 


21-38.59 


.0062957 


450 


24- 


.0069813 


500 


21-36 


.0062831 



398 SHOP AND DRAWING ROOM STANDARDS 



LENGTHS OF CIRCULAR ARCS 

The table gives the lengths of circular 
arcs to the radius of one, for angles from 
I to 1 80 degrees. The lengths for minutes of 
\> arcs are given at the right. 

To find the length of a circular arc with 
radius of i inch and angle of 45 degrees 20 
minutes. Opposite 45 degrees find 0.7854, 
and opposite 20 minutes 0.0058. Adding 
these gives 0.7912 inch as the length of arc. 
radius is 2 inches, multiply the lengths in the table by 2. 

Lengths of Circular Arcs to Radius of i 




De- 
gree 


Length 


De- 
gree 

45 


Length 


De- 
gree 


Length 


De- 
gree 


Length 


Min. 


Length 


Min. 


Length 





0.0000 


0.7854 


90 


1-5708 


135 


2.3562 





0.0000 


45 


0.0131 


I 


0.0175 


46 


0.8029 


91 


1.5882 


136 


2.3736 


I 


0.0003 


46 


0.0134 


2 


0.0349 


47 


0.8203 


92 


1.6057 


137 


2-3911 


2 


0.0006 


47 


0.0137 


3 


0.0524 


48 


0.8378 


93 


1.6232 


138 


2.4086 


3 


0.0009 


48 


0.0140 


4 


0.0698 


49 


0.8552 


94 


1.6406 


139 


2.4260 


4 


0.0012 


49 


0.0143 




0.0873 


50 


0.8728 


95 


1.6581 


140 


2.4435 


5 


0.0015 


50 


0.014s 


6 


0.1047 


51 


0.8901 


96 


1-6755 


141 


2.4609 


6 


0.0017 


51 


0.0148 


7 


0.1222 


52 


0.9076 


97 


1-6930 


142 


2.4784 


7 


0.0020 


52 


0.0151 


8 


0.1396 


53 


0.9250 


98 


1. 7104 


143 


2.4958 


8 


0.0023 


53 


0.0154 


9 


0.1571 


54 


0.9425 


99 


1.7279 


144 


2.5133 


9 


0.0026 


54 


0.0157 


10 


0.1 745 


55 


0.9599 


100 


1-7453 


145 


2.5307 


10 


0.0029 


55 


0.0160 


II 


0.1920 


56 


0.9774 


101 


1.7628 


146 


2.5482 


11 


0.0032 


56 


0.0163 


12 


0.2094 


57 


0.9948 


102 


1.7802 


147 


2.5656 


12 


0.0035 


H 


0.0166 


13 


0.2269 


58 


1.0123 


103 


1.7977 


14S 


2.5831 


13 


0.0038 


S8 


0.0169 


14 


0.2443 


59 


1.0297 


104 


1-8151 


149 


2.6005 


14 


0.0041 


59 


0.0172 


IS 


0.2618 


60 


1.0472 


105 


1.8326 


150 


2.6180 


15 


0.0044 


60 


0.017s 


16 


0.2793 


61 


1.0647 


106 


1.8500 


151 


2.6354 


16 


0.0047 






17 


0.2967 


62 


1.0821 


107 


1-8675 


152 


2.6529 


17 


0.0050 






18 


0.3142 


63 


1.0996 


108 


1.S850 


153 


2.6704 


18 


0.0052 






19 


0.3316 


64 


1.1170 


109 


1.9024 


154 


2.6878 


19 


0.005 s 






20 


6.3491 


65 


I-I345 


110 


1.9199 


155 


2.7052 


20 


0.0058 






21 


0.3665 


66 


1.1519 


111 


1-9373 


156 


2.7227 


21 


0.0061 






22 


0.3840 


67 


1. 1694 


112 


1.9548 


157 


2.7402 


22 


0.0064 






■23 


0.4014 


68 


1. 1868 


113 


1.9722 


158 


2.7576 


23 


0.0067 






24 


0.4189 


69 


1.2043 


114 


1-9897 


159 


2.7751 


24 


0.0070 






25 


0.4363 


70 


1. 2217 


115 


2.0071 


160 


2-7925 


25 


0.0073 






26 


0.4538 


71 


1.2392 


116 


2.0246 


161 


2.8100 


26 


0.0076 






27 


0.4712 


72 


1.2566 


117 


2.0420 


162 


2.8274 


27 


0.0079 






28 


0.4887 


73 


1-2741 


118 


2-0595 


163 


2.8449 


28 


0.0081 






29 


0.5061 


74 


1.2915 


119 


2.0769 


164 


2.8623 


29 


0.0084 






30 


0.5236 


75 


1.3090 


120 


2.0944 


165 


2.8798 


30 


0.00S7 






31 


0.5411 


76 


1.3265 


121 


2.1118 


166 


2.8972 


31 


0.0090 






32 


0.5585 


77 


1-3439 


122 


2.1293 


167 


2.9147 


32 


0.0093 






33 


0.5760 


78 


1.3614 


123 


2.1468 


i58 


2.9322 


33 


0.0096 






34 


0.5934 


79 


r.3788 


124 


2.1642 


169 


2.9496 


34 


0.0099 






35 


0.6109 


80 


1-3963 


125 


2.1817 


170 


2.9671 


35 


0.0102 






36 


0.6283 


8i 


I-4137 


126 


2.1991 


171 


2.9845 


36 


0.0105 






37 


0.6458 


82 


I-4312 


127 


2.2166 


172 


3.0020 


37 


0.0108 






38 


0.6632 


83 


1.4486 


128 


2.2340 


173 


3-0194 


38 


O.OIII 






39 


0.6807 


84 


1.4661 


129 


2-2515 


174 


3-0369 


39 


O.OII3 






40 


0.6981 


85 


1.4835 


130 


2.2690 


175 


3-OS43 


40 


0.0116 






41 


0.7156 


86 


I. 5010 


131 


2.2864 


176 


3-0718 


41 


0.0119 






42 


0.7330 


87 


I-5184 


132 


2.3038 


177 


3-0892 


42 


0.0122 






43 


0.7505 


88 


1-5359 


133 


2.3132 


178 


3-1067 


43 


0.0125 






44 


0.7679 


89 


I-5S33 


134 


2.3387 


179 


3-1241 


44 


0.0128 







BOLT HEAD UPSETS 399 

'Actual Cutting Speed of Planers in Feet per Minute 



Forward Cut- 






Return Speed 






ting Speed 
















in Feet 
















per Minute 


2 to I 


3 to I 


4 to 1 


5 to I 


6 to I 


7 to I 


8 to I 


20 


13.3 


15. 


16 


16.66 


17.14 


17-5 


17.76 


25 


16.6 


18.75 


20 


20.83 


21.42 


21.87 


22.16 


30 


20. 


22.5 


24 


25- 


25-71 


26.25 


26.56 


35 


23-3 


26.25 


28 


29.16 


30- 


30.62 


31.04 


40 


26.6 


30. 


32 


33-33 


34-28 


35- 


35-52 


45 


30. 


33-75 


36 


37 5 


38.56 


39-37 


40. 


50 


33-3 


37-5 


40 


41.66 


42.84 


43-75 


44-48 


55 


36.6 


41.25 


44 


45-83 


47.12 


48.12 


48.95 


60 


40. 


45- 


48 


50- 


51.42 


52.50 


53-43 


65 


43-3 


48.75 


52 


54.16 


55-70 


56.87 


57-91 


70 


46.6 


52.5 


56 


58.33 


60. 


61.25 


62.3 


75 


50. 


56.25 


60 


62.5 


64.28 


66.62 


66.71 



The table shows clearly that a slight increase in cutting speed is 
better than high return speed. A 25-foot forward speed at 4 to i 
return is much better than 8 to i return with 20-feet forward speed. 
Economical planer speeds are given below (Cincinnati Planer Co.). 

Cast Iron roughing 40 to 50 ft.; finishing 20 to 25 ft. 

Steel casting and wrought iron roughing 30 to 35 ft.; finishing 20 ft. 

Bronze and brass. . .50 to 60 ft.; Machinery steel. . .30 to 35 ft. 

ALLOWANCES FOR BOLT HEADS AND UPSETS 

Stock Allowed for Standard Upsets by Acme Machinery Co. 



1 in. 


Upset 


to f ] 


n. 


Length of Up 


set, 3 ir 


1. Stock required, if in. 


8 




5 






32 




3 U 
4 


" 


1 






<■ ol I 

32 


ji 11 


7 (i 


(( 


,.1 






; . I 




8 




l8 






4 


24 




(( 


I4 


a 




' 4 ' 


. a il ,| li 


li " 


" 


if 


u 




' Ah ' 


2\ " 


T- " 


ec 


li 


" 




' Ah ' 


I il 11 2! " 


T- " 


li 


if 


11 




5 


' " " 2\ " 


^ " 


" 


I? 


u 




' 5 ' 


2 " 


li " 


" 


I^ 






5 ' 


' - " 2| " 


5 il 


. " 


l| 


It 




' Sh ' 


. 11 li ^. il 


3 li 


a 


2 


11 




' Sh ' 


i il li j| il 


l| " 


a 


2i 


a 




' 6 ' 


2 " 


2 " 


" 


2| 


" 




' 6 ' 


' u u ,1 11 


2 " 


" 


2h 


li 




' 6 ' 


i il 11 i 11 


2i '' 


(( 


2t 


il 




' 6| ' 


i li 11 ,i 11 


2i " 


u 


2! 


il 




' 6| ' 


2\ " 


2i " 


" 


3I 


" 




7 ' 


I li "2 " 


3 " 


li 


3i 


'i 




' 7 ' 


i il a 2I " 



400 SHOP AND DRAWING ROOM STANDARDS 




"x. 


'.111',' 


1 


1 ' 1 ', ' ' 1 1 1 





Stock Required to Make Manufacturer's Standard Bolt 
Heads and Nuts — Rough 

national machinery CO. 





Bolt Heads 








Nuts 






Square or 


Hexagon 


Square or Hexagon 
















Size Stock 




Short 




Stock 
Required 
for Upset 


Short 






Required 




Diameter 




Diameter 


o 




Width 


Thick- 


■>-> 










W 






ness 






c 








1 






« 


















Square 


1 


Sq. 


Hexa- 
gon 




Sq. 


Hexa- 
gon 


Sq. 


Hexa- 
gon 


6 
.2 

P 


g 


Sq. 


Hexa- 
gon 


or 
Hexa- 
gon 


in. 


in. 


in. 


in. 


in. 


in. 


in. 


in. 


in. 


in. 


in. 


in. 


in. 




1 


/s 


i\ 


• hi 


§1 


h 


§ 


3^5 




41 


M 


ii 


j% 


hi 


^1 


i 


H 


f 


f 


f 


3% 




li 


M 


M 




1% 


1 


Tf^ 


a 


}§ 


I 


a 


-^1 




if 


!l 


5? 


j\ 


U 


M 


1^ 


u 


I 


1 


1 


hi 




if 


ii 


M 




f 


U 


1 


lA 


I3='S 


I 


I 


I'o 




if 


ii 


U 


t\ 


§1 


U 


n 


13^ 


li 


li 


li 


i 




iiV 


Il^e 


hi 




it 


I 


hi 


iH 


iM 


li 


li 


1% 




Ift 


ii\ 


U 




ij 


Il^e 


j% 


if 


ii% 


ij 


If 


si 




Ife 


ii\ 


ii 




lA 


If 


u 


ll 


i| 


If 


If 


§f 




lie^ 


i/s 


ii 




i,^ 


Il% 


. 1 


23-^ 


2;^ 


2 ■ 


If 


1 




lit 


liJ 


ii^ 




lii 


If 


SI 


2^ 


23^5 


2l 


2 


ii 




2^ 


lil 


ii% 




il 


IH 


it 


2iS 


2/s 


2| 


2i 


1 3=^2 




2t 


2A 


i^ 




2xV 


2| 


I^^a 


33". 


2§5 


2| 


2^ 


Il\ 




2f 


2| 


If 




2i 


2A 


l| 


33^. 


3 


3 


2f 


ix''. 




2| 


2f 


If 




2/h 


2^ 


ItTij 


3^1 


3^ 


3i 


3 


I/. 




3l 


2| 


i| 




2f 


2H 


lA 


3f 


3M 


3i 


3f 


Il% 




3f 


3l 


2 




2ii 


2i 


IM 


4'3^. 


3^1 


3f 


3i 


lil 




3f 


3f 


2| 


2 


3 


3iV 


I^ 


41% 


4 


4 


3i 


IH 


2 


3l 


3f 


2i 


aj 


3f 


3^6 


IJI 


5 


41% 


4i 


3f 


2 


2s 


4i 


3f 


2f 


2j 


3f 


351 


l| 


5f 


4il 


4i 


4i 


2i 


22 


4f 


4l 


2f 


2| 


4i 


4i='s 


2l\j 


SM 


5f 


4f 


4i 


2fe 


2f 


4f 


4f 


2| 


3 


4i 


41^6 


2i 


6{, 


Sii 


5 


4f 


2iJ 


3 


45 


4f 


3f 



STOCK FOR BOLT HEADS AND NUTS 



401 





Stock Required to Make United States Standard Bolt 
Heads and Nuts — Rough 



NATIONAL MACHINERY CO. 





Bolt Heads 






Nuts 






Square or Hexagon 






Square or Hexagon 


















Size Stock 








Stock Required 








Required 




Short 
Diam- 
eter 




for Upset 


Short 
Diam- 






Square or 


Size 
of Bolt 


Thick- 
ness 






Diameter 
Hole 


Thick- 
ness 


Hexagon 






Square 


Hexa- 
gon 








Width 


Thick- 
ness 


in. 


in. 


in. 


in. 


in. 


* 
in. 


in. 


in. 


in. 


in. 






i 


IT?2 


ITJ^ 


i 


r\ scant 




'h 


M 


i\ 


M 


M 


if 


It\ 


M 


J scant 


A 


M 


1% 




H 


hi 


ij 


li 


a 


U scant 




§1 


il 


18 


M 


tS 


If 


If 


M 


M 


7« 


11 


Jl 






/s 


i§l 


li 


1 


if scant 




ii 


^1 


I6 


§i 


li 


lit 


•If 


Si 


§1 


j% 


!l 


M 




iiV 


il 


2 


iH 


ii\ 


^ full 


5 




§J 




Is 


1 


2 3'2 


iJI 


li 


f scant 




I?5 


H 




l/a 


il 


2| 


2t.^2 


l/a 


li scant 




If 


il 




If 


if 


2f 


2f 


If 


§1 scant 


I 


Il%- 


ii^ 




iH 


§1 


3 


2M 


lit 


if fuU 




ll 


lA 




2 


I 


3i 


2SI 


2 


11^5 fuU 




l8- 


If 




21^6 


iTf^ 


3t% 


3 


2^\ 


13^5 full 




21^6 


i^ 


^ 


2| 


I A 


3l'e 


3t% 


2f 


13% fuU 




2\ 


If 




2l% 


13% 


4tV 


si 


2t% 


li? scant 




2{, 


If 




2| 


If 


4f 


3l 


2f 


i| scant 




2f 


if 




2if 


iM 


4l 


4 


2if 


if scant 




2ii 


2 




3i 


ii% 


4f 


4i 


3i 


lit scant 




3 


2f 




3h 


If 


S/e 


4§i 


3i 


lU scant 




3f 


2f 




3i 


iM 


5il 


sA 


3i 


2^ 




3f 


2f 


2f 


4i 


2i 


6/e 


s§ 


4i 


2/5 


2? 


4^ 


2i 


3 


4i 


2^ 


7 


6i^ 


4f 


2H 


3 


4i 


3i 



402 SHOP AND DRAWING ROOM STANDARDS 





O OJ 








<0 cj 








-^a 








tfl "p 




IS =3 


s 


H^ 


3 




H 


-&J2 


W 


c o 






Ph 


ci 


'^ 


5 <J 






ft 




Ui 


^1 


M 


G 


Q 


^^ 


^ 


bX) be 


U3- 


cd-r: 


M 


^ Cj 


r^; 


o^ 


^ 


^S 




c o 


Tt 


t^ r^ 


oT 


-^^ 


g 


c ^ 



8|i 









dJ O 

si 

en 



M 0) fO ^ lO t^OO O O M M r}- io>0 ^^00 O M M ro ^ \ri\0 OQ 



M N CO •^ lO^O t^OO 0> O w fO •* l/^vO t^OO O O H N CO "^^O 



H N rO ■^ lovo t^OO 0> O w c^ ro r)- lovO ^~'y5 O O hi N CO ■* 



i-»-i M (N CO •* mvO t^OO Ov O M w <N CO Tf lOvO t^OO 0^ O 



CO -"t »0 ITi'^ t-^00 <> O O 



■51- lo loO r^oo O O 



CO CO "* u~.\o O r^oO 0\OiOmp»cvico'+»o uivO t^OO 



CO ■* '^ lOvO -O t-00 oOOvOOMC^Oico-*^ «'-!0 



M M o cs coco^'+io lO'O O r^ r>-00 oo Oi 0> O O 



''h MHCJlNCSCOCO"=t^lO>0 vo\0 O t^ t^ t^oo 00 0> Oi O 



cococo-*^"+ioio lO^O vo MO t-- t^ r^oO 



cs cocococO'^'+^'^ioio"^ lOvO 



01 c< o< cocococococo 



H^-Hl*rHl-*H«>0/''H|f«t-/ f^ 



* * * *_..*._*, 



CO ^ \ri\0 t^OO Ov O 



% % 6_^S ft % Sr S: ft ft ft 



saqonj ui pjBoa Jo q^pjAV 



WEIGHT OF FILLETS 



403 



QUICK WAY OF ESTIMATING LUMBER FOR A PATTERN 

Multiply length, breadth, and thickness in inches together and 
this by 7, pointing off three places. 

Board 8 inches wide, 18 inches long, i inch thick. 8 X 18 X i 
X 7 = 1.008 square feet. This is .008 too much, but near enough 
for most work. Board i^ X 10 X 36 = 540 X 7 = 3.780. The 
correct answer is 3.75. 

Table Giving Proportionate Weight of Castings to Weight 
OF Wood Patterns 



A Pattern 
Weighing One 
Pound Made of 

(Less weight of 
Core Prints) 


Cast 
Iron 


Brass 


Copper 


Bronze 


Bell 
Metal 


Zinc 


Pine or Fir. . 

Oak 

Beech 

Linden 

Pear 

Birch 

Alder 

Mahogany . . 
Brass 


16 

9 

9-7 
13-4 
10.2 
10.6 
12.8 
II. 7 

0.85 


18.8 
lO.I 

10.9 
15.1 

11.9 

14-3 
13.2 

0.95 


19.7 

10.4 
11.4 
16.7 
II. 9 
12.3 
14-9 
13-7 
0.99 


19.3 
10.3 

II-3 
15-5 
11.8 
12.2 
14.7 
13-5 
0.98 


17 

10.9 

II. 9 

16.3 

12.4 

12.9 

15-5 

14.2 

I.O 


15.5 

8.6 

9.1 

12.9 

9.8 

10.2 

12.2 

II. 2 

0.81 



Degrees Obtained by Opening a Two-Foot Rule 



Degrees 


Inches 


Degrees 


Inches 


Degrees 


Inches 


I 


.21 


15 


3.12 


55 


11.08 


2 


.422 


20 


4.17 


60 


12 


3 


.633 


25 


5.21 


65 


12.89 


4 


.837 


30 


6.21 


70 


13-76 


5 


1.04 


35 


7.20 


75 


14.61 


7-5 


1-57 


40 


8.21 


80 


15-43 


TO 


2.09 


45 


9.20 


85 


16.21 


T4.5 


3-015 


50 


10.12 


90 


16.97 



Open a two-foot rule until open ends are distance apart given 
in table when degrees given in table can be scribed. Same results 
can be had with two 12-inch steel scales placed together at one end. 



404 SHOP AND DRAWING ROOAI STANDARDS 



WEIGHT OF FILLETS 

» 
To facilitate the calculations of the weights of the different parts 
of a machine from the drawings, the accompanying table of areas or 
volumes of fillets having radii from j^g to 3 inches can be used. It 
has been calculated for fillets connecting sides that are at right angles 
to each other. 



Table of Areas or Volumes of Fillets 



Radius of Area 


or Volume 


Radius of 


Area or Volume 


Fillet of F 


illet in Sq. 


Fillet 


of Fillet in Sq. 


in Inches or Ci 


ibic Inches 


in Inches 


or Cubic Inches 


tV 


0008 


It\ 


.5240 


i 


0033 


^f. 


.5667 


A 


0075 


iH 


.6119 


i 


0134 


If 


.6572 


V 


0209 


Iff 


.7050 


1 


0302 


li 


.7543 


tV 


0410 


iM 


.8056 


h 


0537 


2 


.8584 


■h 


0678 


2tV 


.9129 


■ 


0838 


2l • 


.9690 


■i 


1013 


2tV 


1.0269 




1207 


2i 


1.0864 


•1 


1417 


^t\ 


I-I475 


ll 


1643 


2f 


1. 2105 


1886 


2tV 


1.2749 


I 


2146 


2i 


1-3413 


ItV 


2423 


2t% 


1.4086 


li 


2716 


2f 


1.4787 


lA 


3026 


2iJ 


1-5500 


li 


3353 


2f 


1.6229 


'p 


3697 


2}f 


1.6869 


if 


4057 


2I 


1-7739 


ItV - 


4434 


2if 


1.8518 


I^ 


4829 


3 


1.9314 



To find the volume of a fillet by this table when the radius and 
length are given, multiply the value in the table opposite the given 
radius by the length of the fillet in inches, and this result multiplied 
by the weight of a cubic inch of the material will give the weight of 
the fillet. 



USEFUL SUGGESTIONS 405 



LAYING OUT A SQUARE CORNER 

It sometimes happens that we wish to lay out a perfectly square 
corner and have no square of any kind handy. Here is a way that 
requires nothing but a scale or rule, or even a straight stick with- 
out any graduations whatever will do. Using this stick, draw a 
line as ^ C (Fig. i) and at one end of this draw the line B D a.t 
any angle. This line must be straight, twice as long as A C and 




of equal length each side of the point C Then if you join points 
DAB, you have an exact right-angle or square corner. 

Fig. 2 is simply another example of this, in which the line A C 
has been drawn at a very different angle to show that it works in 
any position. Joining the ends D A B a.s before also gives an exact 
right angle. 

ANOTHER METHOD 

Another method is by what is known as the 6, 8 and 10 rule This 
means that if a triangle has sides in the ratio of 6, 8 and 10, the angle 
is 90 degrees. Lay down a line 6 units long, either inches, feet or 
yards. Lay off another hne 8 units long as nearly Tight angles as 
possible. Pleasure across the ends of the two lines and adjust until 
this distance is 10 units, which makes it a right angle. These dis- 
tances may be 3, 4 and 5; 12, 16 and 20 or any combination in this 
ratio. It is largely used in laying out large corners. 

SPEED FOR WOOD TURNING 

A good average speed for a wood turning lathe is a surface or 
cutting speed of from 1,000 to 1,500 ft. per minute. Where work 
does not exceed i-in. diameter the lathe may be run 3,000 r.p.m.; 
for 2-in. stock 2,500; for 3-in., 2,000, or a little less, and for larger 
stock, the speed is reduced in proportion. 

COOLING HOT BEARINGS 

A hot box can be cooled by pouring sulphur on the bearing. It 
melts at 220 degrees and puts a smooth surface on both journals 
and bearings. It fills oil groove but can be dissolved with benzine 
if machine cannot be stopped. Either stick or flowers of sulphur 
will do. Graphite is also good but cannot be used where the color 
^s objectionable as in flour mills or other white stock. 



WIRE GAGES AND STOCK WEIGHTS 



TWIST DRILL AND STEEL WIRE GAGE SIZES 

The Twist Drill and Steel Wire Gage is used for measuring the 
sizes of twist drills and steel drill rods. Rod sizes by this gage should 
not be confused with Stubs' Steel Wire Gage sizes. The difference 
between the sizes of corresponding numbers in the two gages ranges 
from about .0005 to .004 inch, the Stubs sizes being the smaller except 
in the cases of a few numbers where the systems coincide exactly. 

Twist Drill and Steel Wire Gage Sizes 



No. 


Dia. 


No. 


Dia. 


No. 


Dia. 


No. 


Dia. 


of 


in 


of 


in 


of 


in 


of 


in 


Gage 


Inches 


Gage 


Inches 


Gage 


Inches 


Gage 


Inches 


I 


.2280 


21 


.1590 


41 


.0960 


61 


.0390 


2 


.2210 


22 


.1570 


42 


•0935 


62 


.0380 


3 


.2130 


23 


.1540 


43 


.0890 


63 


.0370 


4 


.2090 


24 


.1520 


44 


.0860 


64 


.0360 


5 


.2055 


25 


•1495 


45 


.0820 


65 


•0350 


6 


.2040 


26 


.1470 


46 


.0810 


66 


•0330 


7 


.2010 


27 


.1440 


47 


.0785 


67 


.0320 


8 


.1990 


28 


.1405 


48 


.0760 


68 


.0310 


9 


.i960 


29 


.1360 


49 


.0730 


69 


.02925 


10 


.1935 


30 


.1285 


50 


.0700 


70 


.0280 


II 


.1910 


31 


.1200 


51 


.0670 


71 


.0260 


12 


.1890 


32 


.1160 


52 


•0635 


72 


.0250 


13 


.1850 


33 


.1130 


53 


•0595 


73 


.0240 


14 


.1820 


34 


.1110 


54 


•0550 


74 


.0225 


15 


.1800 


35 


.1100 


55 


,0520 


75 


.0210 


16 


.1770 


36 


.1065 


56 


.0465 


76 


.0200 


17 


•1730 


37 


.1040 


57 


.0430 


77 


,0180 


18 


.1695 


38 


.1015 


58 


.0420 


78 


.0160 


19 


.1660 


39 


•0995 


59 


.0410 


79 


.0145 


20 


.1610 


40 


.0980 


60 


.0400 


80 


.0135 



STUBS' GAGES 

In using Stubs' Gages, the difference between the Stubs Iron Wire 
Gage and the Stubs Steel Wire Gage should be kept in mind. The 
Stubs Iron Wire Gage is the one commonly known as the English 
Standard Wire, or Birmingham Gage, and designates the Stubs soft 
wire sizes. The Stubs Steel Wire Gage is used in measuring drawn 
steel wire or drill rods of Stubs' make and is also used by many 
American makers of drill rods. 

406 



DIFFERENT STANDARDS FOR WIRE GAGES 407 





DIMENSIONS IN DECIMAL PARTS OF 


\N INCH 


Number 


American 
or 


Birm- 
ingham 


Wash- 
bum & 
Moen 
Mfg. Co. 


Trenton 


Stubs' 


Impe- 
rial 
Wire 
Gage 


^ U.S. 


of 


Brown 


or Stubs' 


Iron 


Steel 


Standard 


Gage 


& 
Sharpe 


Iron 
Wire 


Co. 


Wire 


for Plate 


000000 












.464 

•432 
.400 


.46875 

•4375 
.40625 


00000 








•450 
.400 




0000 


'^46 


•454 


•3938* 




000 


.40964 


.425 


•3625 


.360 




•372 


•375 


00 


.3648 


.380 


•3310 


.330 





.348 


•34375 





.32486 


.340 


•3065 


.305 





.324 


•3125 


I 


.2893 


.300 


.2830 


.285 


.227 


•300 


.28125 


2 


•25763 


.284 


.2625 


.265 


.219 


.276 


.265625 


3 


.22942 


.259 


•2437 


.245 


.212 


.252 


•25 


4 


.20431 


• 238 


•2253 


.225 


.207 


.232 


•234375 


5 


.18194 


.220 


.2070 


.205 


.204 


.212 


.21875 


6 


.16202 


.203 


.1920 


.190 


.201 


.192 


.203125 


7 


.14428 


.180 


.1770 


•175 


.199 


.176 


•1875 


8 


.12849 


.165 


.1620 


.160 


.197 


.160 


•171875 


9 


.11443 


.148 


.1483 


.145 


.194 


.144 


.15625 


10 


.10189 


.134 


•1350 


.130 


.191 


.128 


.140625 


if 


.090742 


.120 


.1205 


.1175 


.188 


.116 


.125 


12 


.080808 


.109 


•1055 


.105 


.185 


.104 


.109375 


13 


.071961 


.095 


.0915 


.0925 


.182 


.092 


•09375 


14 


.064084 


.083 


.0800 


.080 


.180 


.080 


.078125 


15 


.057068 


.072 


.0720 


.070 


.178 


.072 


.0703125 


16 


.05082 


.065 


.0625 


.061 


•175 


.064 


.0625 


17 


■045257 


.058 


.0540 


.0525 


.172 


.056 


.05625 


18 


.040303 


.049 


•0475 


.045 


.168 


.048 


•05 


. 19 


•03589 


.042 


.0410 


.040 


.164 


.040 


•04375 


20 


.031961 


•035 


.0348 


.035 


.161 


.036 


•0375 


21 


.028462 


.032 


.03175 


.031 


•157 


.032 


•034375 


22 


.025347 


.028 


.0286 


.028 


.155 


.028 


•03125 


23 


.022571 


.025 


.0258 


.025 


.153 


.024 


.028125 


24 


,.0201 


.022 


.0230 


.0225 


.151 


.022 


•025 


25 


.0179 


.020 


.0204 


.020 


.148 


.020 


.021875 


26 


.01594 


.018 


.0181 


.018 


.146 


.018 


.01875 


27 


.014195 


.016 


•0173 


.017 


.143 


.0164 


.0171875 


28 


.012641 


.014 


.0162 


.016 


.139 


.0149 


.015625 


29 


.01^257 


.013 


.0150 


.015 


.134 


.0136 


.0140625 


30 


.010025 


.012 


.0140 


.014 


.127 


.0124 


.0125 


31 


.008928 


.010 


.0132 


.013 


.120 


.0116 


•0109375 


32 


•00795 


.009 


.0128 


.012 


•115 


.0108 


.01015625 


33 


.00708 


.008 


.0118 


.oil 


.112 


.0100 


•009375 


34 


.006304 


.007 


.0104 


.010 


.110 


.0092 


•00859375 


35 


.005614 


•005 


•0095 


.0095 


.108 


.0084 


.0078125 


36 


.005 


.004 


.0090 


.009 


.106 


.0076 


.00703125 


37 


.004453 






.0085 


.103 


.0068 


.006640625 


38 


•003965 






.008 


.101 


.0060 


.00625 


39 


•003531 






•0075 


.099 


.0052 




40 


•003144 






.007 


•097 


.0048 





4o8 WIRE GAGES AND STOCK WEIGHTS 

Wire and Drill Sizes Arranged Consecutively 





u 




p 


1 


T3 




S 


1 

w 


v2 


a2i 


Dia. of 
Wire 


•Cca 




2^ 


s 


Dia. of 
Wire 




0. 


2^ 






< 


m 


V3 


H 




< 


pa 


c 


H 




Gage Number 


Gage Number 


.00314 


40 








.041 






58 


59 


•00353 


39 








.042 




19 


57 


58 


.00397 


38 








.043 








57 


.004 




36 






.045 






56 




• .0045 


37 








.0453 


17 








.005 


36 


35 






.0465 








56 


.0056 


35 








.049 




18 






.0063 


34 








.050 






55 




.007 




34 






.0508 


16 








.0071 


33 








.052 








55 


.008 • 


32 


33 






.055 






54 


54 


.0089 


31 








.0571 


15 








.009 




32 






.058 




17 


53 




.010 


30 


31 






.0595 








53 


.0113 


29 








.063 






• 52 




.012 




30 






•0635 








52 


.0126 


28 








.0641 


14 








.013 




29 


80 




.065 




16 






.0135 








80 


.066 






51 




.014 




28 


79 




.067 








51 


.0142 


27 








.069 






50 




.0145 








79 


.070 








50 


.015 






78 




.072 


13 


15 


49 




.0159 


26 








•073 








49 


.016 




27 


77 


78 


.075 






48 




.0179 


25 








.076 








48 


.018 




26 


76 


77 


.077 






47 




.020 




25 


75 


76 


.0785 








47 


.0201 


24 








.079 






46 




.021 








75 


.0808 


12 








.022 




24 


74 




.081 






45 


46 


.0225 








74 


.082 








45 


.0226 


23 








.083 




14 






.023 






73 




.085 






44 




.024 






72 


73 


.086 








44 


.025 




23 




72 


.088 






43 




.0253 


22 








.089 








43 


.026 






71 


71 


.0907 


II 








,027 






70 




.092 






42 




.028 




22 




70 


•0935 








42 


.0285 


21 








•095 




13 


41 




.029 






69 




.096 








4t 


.0293 








69 


.097 






40 




.030 






68 




.098 








40 


.031 






67 


68 


.099 






39 




.032 


20 


21 


66 


67 


.0995 








39 


•033 






65 


66 


.101 






38 




.03s 




20 


64 


65 


.1015 








38 


•0359 


19 








.1019 


10 








.036 






63 


64 


.103 






37 




.037 






62 


63 


.104 








37 


.038 






61 


62 


.106 






36 




•039 






6o 


61 


.1065 








36 


.040 






59 


60 


.108 






35 




.0403 


18 

















WIRE AND DRILL SIZES 



409 



Wire and Drill Sizes Arranged Consecutively 





S 


1 


1 
w 


'1 




b 




1 


T3 

^2J 


Dia. of 
Wire 


gv5 




"11 




Dia. of 
Wire 


«c/5 


li 


u 


i 

^C/3 




m 


O) 


H 




< 


pq 


CO 


H 




Gage Number 


Gage Number 


.109 




12 






.203 




6 






.110 






34 


35 


.204 






5 


6 


•III 








34 


.2043 


4 








.112 






33 




.2055 








5 


.113 








33 


.207 






4 




.1144 


9 








.209 








4 


•115 






32 




.212 






3 




.116 








32 


.213 








3 


.120 




11 


31 


31 


.219 






2 




.127 






30 




.220 




5 






.1285 


8 






30 


.221 








2 


.134 




10 


29 




.227 






I 




.136 








29 


.228 








X 


.139 






28 




.2294 


3 








.1405 








28 


.234 






A 




.143 






27 




.238 




4 


B 




.144 








27 


.242 






C 




.1443 


7 








.246 






D 




•146 






26 




.250 






E 




.147 








26 


.257 






F 




.148 




9 


25 




.2576 


2 








.1495 








25 


.259 




3 






•151 






24 




.261 






G 




.152 








24 


.266 






H 




.153 






23 




.272 






I 




•154 








23 


.277 






J 




.155 






22 




.281 






K 




.157 






. 21 


22 


.284 




2 






.159 








21 


.2893 


I 








.161 






20 


20 


.290 






L 




.162 


6 








.295 






M 




.164 






19 




.300 




I 






.165 




8 






.302 






N 




.166 








19 


.316 











.168 






18 




.323 






P 




.1695 








18 


.3249 











.172 






17 




.332 






Q 




.173 








17 


.339 






R 




.175 






16 




.340 











.177 








16 


.348 






S 




.178 






15 




.358 






T 




.180 




7 


14 


15 


.3648 


■ 00 








.1819 


5 








.368 






u 




.182 






13 


14 


.377 






V 




.185 






12 


13 


.380 




00 






.188 






II 




.386 






W 




.189 








12 


.397 






X 




.191 






10 


II 


.404 






Y 




.1935 








10 


.4096 


000 








.194 






9 




.413 






Z 




.196 








9 


.4?S 




000 






.197' 






8 




.454 




QOOO 






.199 






7 


8 


.469 


0000 








J?QI 






<^ 


7 













4IO 



WIRE GAGES AND STOCK WEIGHTS 



STUBS' STEEL WIRE SIZES AND WEIGHTS 

As stated in the explanatory note regarding Stubs' Gages at the 
bottom of page 406 the Stubs steel wire gage is used for measuring 
drawn steel wire and drill rods of Stubs' make and is also used by 
various drill rod makers in America. 

Stubs' Steel Wire Sizes, and Weight in Pounds per Linear Foot 



Letter 


Dia. 


Weight 


No. of 


Dia. 


Weight 


No. of 


Dia. 


Weight 


and No. 


in 


per 


Wire 


in 


per 


Wire 


in 


per 


of Gage 


Inches 


Foot 


Gage I 


nches 


Foot 

1 


Gage 


Inches 


Foot 


z 


.413 


.456 


ID 


191 


.098 


46 


.079 


.017 


Y 


.404 


•437 


II 


1S8 


•095 


47 


.077 


.016 


X 


•397 


.422 


12 


185 


.092 


48 


•075 


.015 


W 


.386 


.399 


13 


182 


.089 


49 


.072 


.014 


V 


.377 


.380 


14 


180 


.087 


50 


.069 


.013 


u 


.368 


.362 


15 


178 


•085 


51 


.066 


.012 


T 


.358 


.335 


16 


175 


.082 


52 


.063 


.Oil 


s 


.348 


.324 


17 


172 


.079 


53 


.058 


.009 


R 


•339 


•3^1 


18 


168 


•075 


54 


•055 


.008 


Q 


.332 


.295 


19 


164 


.072 


55 


.050 


.007 


p 


•323 


.280 


20 


161 


.069 


56 


.045 


.006 





•316 


.267 


21 


157 


.066 


57 


.042 


.0047 


N 


.302 


• 244 


22 


155 


.064 


58 


.041 


.0045 


M 


.295 


233 


23 


153 


.063 


59 


.040 


.0042 


L 


.290 


.225 


24 


151 


.061 


60 


.039 


.0040 


K 


.281 


.211 


25 


148 


.059 


61 


.038 


.0039 


J 


•277 


.205 


26 


146 


•057 


62 


•037 


.0037 


I 


.272 


.192 


27 


143 


•055 


^3 


.036 


•0035 


H 


.266 


.189 


28 


139 


.052 


64 


.035 


.0033 


G 


.261 


.182 


29 


134 


.048 


65 


-033 


.0029 


F 


.257 


.177 


30 


127 


• 043 


66 


.032 


.0027 


E 


.250 


.167 


31 


120 


•039 


67 


.031 


.0026 


D 


.246 


.162 


32 


115 


•035 


68 


.030 


,0024 


C 


.242 


•159 


33 


112 


.034 


69 


.029 


.0022 


B 


• 238 


.152 


34 


IIO 


.032 


70 


.027 


.0020 


A 


• 234 


.146 


35 


108 


.031 


71 


.026 


.0018 


I 


.227 


.138 


36 


106 


.030 


72 


.024 


,0015 


2 


.219 


.128- 


37 


.103 


.028 


73 


.023 


.0014 


3 


.212 


.120 


38 


.101 


.027 


74 


.022 


.0013 


4 


.207 


.115 


39 


.099 


.026 


75 


.020 


.0011 


5 


.204 


.III 


40 


.097 


.025 


76 


.018 


.0009 


6 


.201 


.108 


41 


•095 


.024 


77 


.016 


.0007 


7 


.199 


.106 


42 


.092 


.023 


78 


.015 


,0006 


8 


.197 


.104 


43 


.08S 


.020 


79 


.014 


.0005 


9 


.194 


.101 


44 
45 


.085 
.081 


.019 
.018 


80 


•013 . 


.0004 



WEIGHTS OF SHEET STEEL AND IRON 41 1 



Music Wire Sizes 



No. of 
Gage 


Wash- 
burn & 
Moen 


Webster 

& 
Horsefall 


No. of 
Gage 


Wash- 
burn & 
Moen 


Webster 

& 
Horsefall 


No. of 
Gage 


Wash- 
burn & 
Moen 


Webster 

& 
Horsefall 


8-0 


•00S3 




6 


.0215 


.016 


19 


.0414 


.043 


7-0 


.0087 




7 


.023 


.018 


20 


.0434 


.045 


6-0 


.0095 




8 


.0243 


.020 


21 


.046 


.047 


5-0 


.010 




9 


.0256 


.022 


22 


.0483 


.052 


4-0 


.Oil 


.006 


10 


.027 


.024 


23 


.051 


•055 


3-0 


.012 


.007 


II 


.0284 


.026 


24 


•055 


.059 


2-0 


•0133 


.008 


12 


.0296 


.029 


25 


.0586 


.061 


i-o 


.0144 


.009 


13 


.0314 


.031 


26 


.0626 


.065 


I 


.0156 


.010 


14 


.0326 


'O33 


27 


.0658 


.070 


2 


.0166 


.Oil 


IS 


.0345 


•035 


28 


.072 


.072 


3 


.0178 


.012 


16 


.036 


-037 


29 


.076 


.077 


4 


.0188 


.013 


17 


•0377 


.039 


30 


.080 


.083 


5 


.0202 


.014 


18 


•0395 


.041 









Weights of Sheet Steel and Iron 

united states standard gage 

(Adopted by U. S. Government, July i, 1893) 



Number 
of 


App. 


Weight per Sq. Foot 


No. 
of 


App. 


Weight per Sq. Foot 


Thickness 






Thickness 






Gage 


Steel 


Iron 


Gage 


Steel 


Iron 


0000000 


•5 


20.320 


20.00 


17 


.05625 


2.286 


2.25 


000000 


.46875 


19.050 


18.75 


18 


•05 


2.032 


2. 


00000 


•4375 


17.780 


17-50 


19 


•04375 


1.778 


1^75 


0000 


.40625 


16.510 


16.25 


20 


•0375 


1.524 


1.50 


000 


•375 


15.240 


15.00 


21 


•03437 


1-397 


1-375 


00 


•34375 


13.970 


13-75 


22 


•03125 


1.270 


1.25 





•3125 


12.700 


12.50 


23 


.02812 


1-143 


1. 125 


I 


.28125 


11.430 


11.25 


24 


• 025 


1. 016 


I. 


2 


.26562 


10.795 


10.625 


25 


.02187 


.903 


.875 


3 


•25 


10.160 


10.00 


26 


•01875 


.762 


.75 


4 


•23437 


9-525 


9-375 


27 


.01718 


.698 


.687 


5 


.21875 


8.890 


8.75 


28 


.01562 


.635 


.623 


6 


.20312 


8.255 


8.125 


29 


.01406 


.571 


.562 


7 


•1875 


7.620 


7.5 


30 


•0125 


.508 


.5 


8 


.17187 


6.985 


6.875 


31 


.01093 


.440 


.437 


9 


• 15625 


6.350 


6.25 


32 


.01015 


.413 


.406 


10 


.14062 


5-715 


5.625 


33 


.00937 


.381 


•375 


II 


.125 


5.080 


5.00 


34 


.00859 


.349 


.343 


12 


.10937 


- 4.445 


4.375 


35 


.00781 


.317 


.312 


13 


•09375 


3.810 


3-75 


36 


•00703 


.285 


.281 


14 


.07812 


3.175 


3-125 


37 


.00664 


.271 


.265 


15 


.07031 


2.857 


2.812 


38 


.00625 


.254 


.25 


16 


.0625 


2.540 


2.50 











Weight of I cubic foot is assumed to be 487.7 lbs. for steel plates 
and 480 lbs. for iron plates. 



412 



WIRE GAGES. AND STOCK WEIGHTS 



Weights of Steel, Wrought Iron, Brass and Copper Plates 

AMERICAN or BROWN & SHARPE GAGE 



No. 


Thickness 


Weight in Lbs. per Square Foot 


of 
Gage 












m 
Inches 


Steel 


Iron 


Brass 


Copper 


OOOO 


.46 


1S.77 


18.40 


19.688 


20.838 


OOO 


.4096 


16.71 


16.38 


17-533 


18-557 


oo 


.3648 


14.88 


14-59 


15-613 


16.525 


o 


.3249 


13.26 


13.00 


13.904 


14.716 


r 


.2893 


11.80 


11-57 


12.382 


13-105 


2 


.2576 


• IO-5I 


10.30 


11.027 


11.670 


3 


.2294 


9-39 


9.18 


9.819 


10.392 


4 


.2043 


8.34 


8.17 


8-745 


9-255 


5 


.1819 


7.42 


7.28 


7.788 


8.242 


6 


.1620 


6.61 ■ 


6.48 


6-935 


7-340 


■ 7 


.1443 


5-89 


5-77 


6-175 


6.536 


8 


.1285 


5-24 


5-14 


5-499 


5-821 


9 


.1144 


4.67 


4-58 


4.898 


5-183 


lO 


.1019 


4.16 


4-08 


4-361 


4.616 


II 


.0908 


3-70 


3-63 


3.884 


4.110 


12 


.0808 


3-30 


3-23 


3-458 


3.660 


13 • 


.0720 


2.94 


2.88 


3.080 


3.260 


14 


.0641 


2.62 


2.56 


2-743 


2.903 


IS 


.0571 


2.33 


2.28 


2.442 


2.585 


i6 


.0508 


2.07 


2.03 


2.175 


2.302 


17 


.0453 


1.85 


1.81 


1-937 


2-050 


i8 


.0403 


1.64 


1.61 


1-725 


1-825 


19 


•0359 


1.46 


1.44 


1-536 


1.626 


20 


.0320 


I -3 1 


1.28 


1-367 


1.448 


21 


.0285 


1. 16 


1. 14 


1. 218 


1.289 


22 


.0253 


1.03 


1. 01 


1.085 


1. 148 


22> 


.0226 


.922 


.904 


.966 


1.023 


24 


.0201 


.820 


.804 


.860 


.910 


25 


.0179 


.730 


.716 


.766 


.811 


26 


.0159 


.649 


.636 


.682 


.722 


27 


.0142 


•579 


.568 


.608 


.643 


28 


.0126 


.514 


.504 


.541 


.573 


29 


.0113 


.461 


•452 


.482 


.510 


30 


.0100 


.408 


.400 


.429 


.454 


31 


.0089 


.363 


.356 


.382 


.404 


32 


.0080 


.326 


.320 


.340 


.360 


33 


.0071 


.290 


.284 


'0<^Z 


.321 


34 


.0063 


•257 


.252 


.269 


.286 


35 


.0056 


.228 


.224 


.240 


.254 


36 


,0050 


.190 


.188 


.214 


.226 


37 


.0045 


.169 


.167 


.191 


.202 


38 


.0040 


.151 


.149 


.170 


.180 


39 


•0035 


.134 


.132 


.151 


.160 


40 


,0031 


.119 


.118 


.135 


.142 



WEIGHTS OF SHEET METAL 



413 



Weights of Steel, Wrought Iron, Brass and Copper Plates 
birmingham or stubs' gage 



No. 
of 


Thickness 

in 

Inches 


Weight in Lbs. per Square Foot 


Gage 


Steel 


Iron 


Brass 


Copper 


0000 


.454 


18.52 


18.16 


19.431 


20.556 


000 


.425 


17-34 


17.00 


18.190 


19-253 


00 


.380 


15-30 


15.20 


16.264 


17.214 





•340 


13-87 


13.60 


14-552 


15.402 


I 


.300 


12.24 


12.00 


12.840 


13-590 


2 


.284 


11-59 


11.36 


12.155 


12.865 


3 


.259 


10-57 


10.36 


11.085 


11.733 


4 


.238 


9.71 


9-52 


10.186 


10.781 


5 


.220 


8.98 


8.80 


9.416 


9.966 


6 


.203 


8.28 


8.12 


8.689 


9.196 


7 


.180 


7-34 


7.20 


7.704 


8.154 


8 


•165 


. 6.73 


6.60 


7.062 


7-475 


9 


.148 


6.04 


5-92 


6.334 


6.704 


10 


.134 


5-47 


5-36 


5-735 


6.070 


II 


.120 


4.90 


4.80 


5-137 


5-436 


12 


.109 


4-45 


4-36 


4.667 


4-938 


13 


.095 


3-88 


3.80 


4.066 


4-303 


14 


.083 


3-39 


3-32 


3-552 


3.769 


15 


.072 


2.94 


2.88 


3.081 


3.262 


16 


.065 


2.65 


2.60 


2.782 


2-945 


17 


.058 


2-37 


2.32 


2.482 


2.627 


18 


.049 


2.00 


1.96 


2.097 


2.220 


19 


.042 


1. 71 


1.68 


1.797 


1.902 


20 


.035 


1-43 


1.40 


1.498 


1.585 


21 


.032 


1-31 


1.28 


1.369 


1.450 


22 


.028 


1. 14 


1. 12 


1. 198 


1.270 


23 


.025 


1.02 


1. 00 


1.070 


1. 132 


24 


.022 


.898 


.88 


.941 


.997 


25 


.020 


.816 


.80 


.856 


.906 


26 


.018 


.734 


•72 


.770 


.815 


27 


.016 


.653 


.64 


.685 


.725 


28 


.014 


.571 


.56 


.599 


.634 


29 


.013 


•530 


.52 


.556 


.589 


30 


.012 


.490 


.48 


.514 


.544 


31 


.010 


.408 


.40 


.428 


.453 


32 


.009 


.367 


.36 


.385 


.408 


33 


.008 


.326 


•32 


.342 


.362 


34 


.007 


.286 


.28 


.2996 


.317. 


35 


.005 


.204 


.20 


.214 


.227 


36 


.004 


.163 


.16 


.171 


.181 



414 



WIRE GAGES AND STOCK WEIGHTS 



Weights or Steel, Iron, Brass and Copper Wire 

AMERICAN OR BROWN & SHARPE GAGE 



No. 

of 

Gage 


Dia. 

in 

Inches 


Weight in Lbs. per iooo Linear Feet 


Steel 


Iron 


Brass 


Copper 


oooo 


.4600 


566.03 


560.74 


605.18 


640.51 


ooo 


.4096 


448.88 


444.68 


479-91 


507.95 


oo 


.3648 


355-99 


352.66 


380.67 


402.83 


o 


.3247 


282.30 


279.67 


301.82 


319-45 


I 


.2893 


223.89 


221.79 


239-35 


253-34 


2 


.2576 


177-55 


175-89 


189.82 


200.91 


3 


.2294 


140.80 


139.48 


150.52 


159-32 


4 


.2043 


III. 66 


110.62 


119.38 


126.35 


5 


.1819 


88.548 


87.720 


94.666 


100.20 


6 


.1620 


70.221 


69-565 


75-075 


79-462 


7 


.1447 


55-685 


55-165 


59-545 


63-013 


8 


.1285 


44.164 


43-751 


47.219 


49.976 


9 


.1144 


35.026 


34-699 


37-437 


39-636 


lO 


.1019 


27.772 


27.512 


29.687 


31.426 


II 


.0907 


22.026 


21.820 


23-549 


24.924 


12 


.0808 


17.468 


17-304 


18.676 


19.766 


13 


.0720 


13-851 


13.722 


14.809 


15-674 


14 


.0641 


10.989 


10.886 


IT. 746 


12.435 


15 


.0571 


8.712 


8.631 


9-315 


9-859 


i6 


.0508 


6.909 


. 6.845 


7-587 


7.819 


17 


•0453 


5-478 


5-427 


5-857 


6.199 


i8 


.0403 


4-344 


4.304 


4-645 


4.916 


19 


•0359 


3-445 


3.413 


3.684 


3-899 


20 


.0320 


2.734 


2.708 


2.920 


3-094 


21 


.0285 


2.167 


2.147 


2.317 


2.452 


22 


•0253 


1. 719 


1-703 


1.838 


1.945 


23 


,0226 


1-363 


1.350 


1.457 


T.542 


24 


.0201 


1.081 


1. 071 


I-I55 


1.223 


25 


.0179 


.8571 


.8491 


.9163 


.9699 


26 


.0159 


.6797 


•6734 


.7267 


.7692 


27 


.0142 


•5391 


.5340 


.5763 


.6099 


28 


.0126 


.4275 


•4235 


.4570 


.4837 


29 


.0113 


.3389 


.3358 


.3624 


.3835 


30 


.0100 


.2688 


.2663 


.2874 


.3042 


31 


,0089 


.2132 


.2113 


.2280 


.2413 


32 


.0080 


.1691 


•1675 


.1808 


.1913 


33 


.0071 


.1341 


.1328 


.1434 


.1517 


34 


.0063 


.1063 


.1053 


.1137 


.1204 


^1 


.0056 


.0844 


.0836 


.0901 


.0956 


36 


.0050 


.0668 


.0662 


.0715 


.0757 


37 


.0045 


. -0530 


•0525 


.0567 


.0600 


38 


.0040 


.0420 


.0416 


.0449 


.0475 


39 


•0035 


.0333 


.0330 


.0356 


.0375 


40 


.0031 


.0264 


.0262 


.0282 


.0299 



WEIGHTS OF WIRE 



415 



Weights of Iron, Brass, and Copper Wire 
birmingham or stubs' gage 



Dia. 

in 

Inches 



•454 
.425 
.380 
.340 
.300 
.284 

.259 
.238 
.220 
.203 
.180 
.165 
.148 
.134 
.120 
.109 

.095 
.083 
.072 
.065 
.058 
.049 
.042 

.035 
.032 
.028 
.025 
.022 
.020 
.018 
.016 
.014 
.013 
.012 
.010 
.009 
.008 
.007 
.005 
.004 



Weight in Lbs. per iooo Linear Feet 



Iron 



546.21 
478.65 
382.66 

306.34 
238.50 

213-74 

177-77 

150.11 

128.26 

109.20 

85.86 

72.14 

58-05 

47-58 

38.16 

31-49 
23.92 
18.26 

13-73 

II. 19 

8.92 

6.36 

4.67 

3-25 
2.71 
2.08 
1.66 
1.28 
1.06 
.863 
.680 
.529 
.438 
.382 
.266 
.212 
.167 

•133 
.066 
.046 



Brass 



589.29 
516.41 
412.84 
330.50 
257-31 
230.60 
191.79 
161.95 

138.37 

117.82 

92.63 

77-83 
62.62 

51-34 
41.17 

33-97 

25.80 

19.70 

14.82 

12.08 

9.62 

6.86 

5-04 

3-52 

2.93 

2.24 

1.79 

1-39 
1. 14 
.926 
.732 
.560 

.483 
.412 
.286 
.232 
.183 
.140 
.071 
.048 



Copper 



623.2 
546.1 
436.6 

349-5 
272.1 

243-9 
202.8 

171-3 

146.3 

124.6 
97.96 
82.31 
66.23 
54.29 
43-54 
35-92 
27.29 
20.83 

15-67 
12.77 
10.17 
7-259 
5-333 
3-704 
3.096 
2.370 
1.890 
1.463 
1.209 
.979 
•774 
•592 
.511 
.435 
•302 
.244, 

•193 
.148 

.075 
^052 



4i6 



WIRE GAGES AND STOCK WEIGHTS 



Weights of Steel and Iron Bars per 


Linear Foot 


Dia. or Dis- 


Steel | 


Iron 


tance Across 




Weight 


per Foot 




Weight per Foot 


Flats 


Round 


Square 


Hexagon 


Octagon 


Round 


Square 


^ 


• OIO 


.013 


.012 


.Oil 


.010 


.013 


i 


.042 


.053 


.046 


.044 


.041 


.052 


t\ 


.094 


.119 


.103 


.099 


.092 


.117 


i 


.167 


.212 


.185 


.177 


.164 


.208 


A 


.261 


•333 


.288 


.277 


.256 


•326 


1 


•375 


.478 


.414 


.398 


.368 


.469 


^ 


•511 


.651 


.564 


•542 


•501 


•638 


h 


.667 


.850 


•737 


.708 


•654 


•833 


t\ 


.845 


1.076 


.932 


.896 


.828 


1.055 


1 


1-043 


1.328 


1. 151 


1. 107 


1.023 


1.302 


ii 


1.262 


1.608 


1.393 


I.33I 


1.237 


1.576 


i 


1.502 


1.913 


1.658 


1.584 


1.473 


1.875 


H 


1.763 


2.245 


1.944 


1.860 


1.728 


2.201 


1 


2.044 


2.603 


2.256 


2.156 


2.004 


2.552 


il 


2.347 


2.989 


2.591 


2.482 


2.301 


2.930 


I 


2.670 


3.400 


2.947 


2.817 


2.618 


3-333 


itV 


3.014 


3.838 


3'327 


3.182 


2.955 


3.763 


li 


3.379 


4.303 


3.730 


3.568 


3-3^3 


4.219 


it\ 


3.766 


4.795 


4.156 


3.977 


3.692 


4.701 


li 


4.173 


5.312 


4.605 


4.407 


4.091 


5.208 


lA 


4.600 


5.857 


5.077 


4.858 


4.510 


5.742 


If 


5-049 


6.428 


5.571 


5.331 


4.950 


6.^02 


itV 


5.518 


7.026 


6.091 


5.827 


5.410 


6.888 


I^ 


6.008 


7.650 


6.631 


6.344 


5.890 


7.500 


IT^6 


6.520 


8.301 


7.195 


6.905 


6.392 


8.138 


if 


7.051 


8.978 


7.776 


7.446 


6.913 


8.802 


iH 


7.604 


9.682 


8.392 


8.027 


7.455 


9.492 


If 


8.178 


10.41 


9.025 


8.635 


8.018 


10.21 


iH 


8.773 


II. 17 


9.682 


9.264 


8.601 


10.95 


i| 


9.388 


11.95 


10.36 


9.918 


9.204 


11.72 


lit 


10.02 


12.76 


11.06 


10.58 


9.828 


12.51 


2 


10.68 


13.60 


11.79 


11.28 


10.47 


13.33 


2| 


12.06 


15.35 


13.31 


12.71 


11.82 


15.05 


2? 


13.52 


17.22 


14.92 


14.24 


13.25 


16.88 


2| 


15.07 


19.18 


16.62 


15.88 


14.77 


18.80 


2h 


16.69 


21.25 


18.42 


17.65 


16.36 


20.83 


2f 


18.40 


23.43 


20.31 


19.45 


18.04 


22.97 


2| 


20.20 


25.71 


22.29 


21.28 


19.80 


25.21 


2| 


22.07 


2S.10 


24.36 


23.28 


21.64 


27.55 


3 


24.03 


30.60 


26.53 


25.36 


23.56 


30.00 


3i 


26.08 


33.20 


28.78 


27.50 


25.57 


32.55 


3i 


28.20 


35.92 


31.10 


29.28 


27.65 


35.21 


3l 


30.42 


38.78 


33.57 


32.10 


29.82 


37-97 


3^ 


32.71 


41.65 


36.10 


34.56 


32.07 


40.83 


3f 


35.09 


44.68 


38.73 


37.05 


34.40 


43.80 


3f 


37.56 


47.82- 


41.45 


39.68 


36.82 


46.88 


3l 


40.10 


51.05 


44.26 


42.35 


39.31 


50.05 


4 


42.73 


54.40 


47.16 


45.12 


41.89 


53-33 



WEIGHTS OF BAR STOCK 



417 



Weights of Brass, Copper and 


Aluminum Bars 


PER Linear Foot 


Dia. or 


Brass 


Copper 


Aluminum 


Dis- 
tance 
Across 
Flats 


Weight per Foot 


Weight 


per Foot 


Weight 


per Foot 


Round 


Square 


Hexagon 


•Round 


Square 


Round 


Square 


tV 


.oil 


.014 


.013 


.012 


.015 


.003 


.004 


k 


.045 


.055 


.048 


.047 


.060 


.014 


.018 


t\ 


.100 


•125 


.108 


.106 


•135 


.032 


.041 


i 


•175 


.225 


.194 


.189 


.241 


.057 


.072 


t\ 


•275 


•350 


.301 


.296 


•377 


.089 


.114 


t 


•395 


.510 


.436 


.426 


.542 


.128 


.163 


t\ 


.540 


.690 


.592 


.579 


•737 


.174 


.222 


^ 


.710 


.905 


.773 


•757 


•964 


.227 


.290 


t\ 


.900 


I-I5 


.978 


.958 


1.22 


.288 


.367 


f 


1. 10 


1.40 


1.24 


1. 18 


1-51 


.356 


•453 


u 


'•^1 


1.72 


1-45 


1-43 


1.82 


.430 


.548 


f 


1.66 


2.05 


1-73 


1.70 


2.17 


.516 


.652 


if 


1.85 


2.40 


2.03 


2.00 


2.54 


.601 


.766 


7 

1" 


2.15 


2-75 


2.36 


2.32 


2-95 


.697 


.888 


H 


2.48 


3-15 


2.71 


2.66 


3-39 


.800 


1.02 


I 


2.8s 


3-65 


3.10 


3-03 


3.86 


.911 


1. 16 


itV 


3.20 


4.08 


3-49 


3-42 


4-35 


1.03 


I-3I 


li 


3-57 


4-55 


3-91 


3.81 


4.88 


I-I5 


1.47 


lA 


3-97 


5.08 


4-38 


4.27 


5-44 


1.28 


1.64 


li 


4.41 


5-65 


4.82 


4.72 


6.01 


1.42 


1.81 


lA 


4.86 


6.22 


5-33 


5-21 


6.63 


1-57 


2.00 


if 


5-35 


6.81 


5-76 


5-72 


7.24 


1.72 


2.19 


ItV 


5.86 


7-45 


6.38 


6.26 


7-97 


1.88 


2.40 


ih 


6.37 


8.13 


6.92 


6.81 


8.67 


2.05 


2.61 


iys 


6.92 


8.83 


7-54 


7-39 


9.41 


2.22 


2.83 


if 


7.48 


9-55 


8.15 


7-99 


10.18 


2.41 


3.06 


IH 


8.05 


10.27 


8.80 


8.45 


10.73 


2.59 


•3-30 


if 


8.65 


11.00 


9-47 


9.27 


11.80 


2.79 


3-55 


iH 


9.29 


11.82 


10.15 


9.76 


12.43 


2.99 


3.81 


ll 


9-95 


12.68 


10.86 


10.64 


13-55 


3-20 


4.08 


iM 


10.58 


13-50 


11.68 


II. II 


14-15 


3-41 


4-35 


2 


11.25 


14-35 


12.36 


12. II 


15.42 


3-64 


4-64 


2i 


12.78 


16.27 


13.92 


13-67 


17.42 


4.11 


5-24 


2i 


14.32 


18.24 


15-72 


15-33 


19-51 


4.61 


5-87 


2| 


15.96 


20.32 


17-52 


17.08 


21.74 


5-14 


6.54 


2^ 


17.68 


22.53 


19.44 


18.92 


24.09 


5-69 


7-25 


2f 


19-50 


24-83 


21.24 


20.86 


26.56 


6.27 


7-99 


2f 


21.40 


27-25 


23-40 


22.89 


29.05 


6.89 


8.53 


2| 


23-39 


29-78 


25.82 


25.02 


31.86 


7-52 


9-58 


3 


25-47 


32-43 


27.84 


27.24 


34-69 


8.20 


10.44 


3i 


30-45 


38.77 


32.76 


31-97 


40.71 


9.62 


12.25 


3^ 


35-31 


44-96 


37-80 


37-08 


47.22 


II. 16 


14.21 


3f 


40.07 


51.01 


43-56 


42.11 


53-61 


/2.81 


16.31 


4 


46.12 


58-73 


49-44 


48.43 


61.67 


14.56 


18.56 



4i8 



WIRE GAGES AND STOCK WEIGHTS 



vO 


\0 ro 
up 00 


M 00 
M op 


NO n 
NO On 
!>. 00 


O O 
CM VO 

d M 


00 O O 00 
!>. q ro NO 00 

w ■^ VO NO r^ 




M 

On 


o 


VO M 

On no 

pj VO d 

N CN ro 


in 




o 


VO N O Tl- 
N CO ^ '^ 

■rj- lo vd r~- 


(M NO 
VO VO 

00 .On 


Tt- O O 6 N 

NO !>. 00 00 On 

d M C^ ro 4 

M M M M M 


VO 




t^ O NO 

M rp up 
On M VO 

M n P^ 


^ 


o 

M 




O u-> 


O U-) o lO 

M On 00 NO 
VO VO NO X>. 


cs VO O O P< O 
VO ro M M On 00 
00 On d M M <S 


CO 

M 


GOO 
CO O T 




M 




00 <N 
On 1>- 
cJ ro 


NO M 

4 uH 


NO On 
On no 

VO NO* 


•^ 00 <N t^ <N 
Tf M On NO ■^ 
!>. 00 00 On d 


O 


On 


-^ On 00 
ro 4 t^ 


ro 


^ 


On 


o o, 

VO M 


ro NO 
CO 't 


O "T ON M VO On •^ 
M !>. ro O NO M On 

VO VO NO t^ r^ 00 00 


NO 
VO 

On 


O 
P) 

d 


00 NO o 
^ r^ rp 

w pi VO 


IT 


00 

M 




ro On 




CO NO 
NO <N 

4 u^ 


NO ro <N O On 
00 ^ q NO M 
VO NO !>• !>. 00 


CO 


NO 

CO 
On 


VO !>. O 

d M TJ- 


rtiri 


q 


^. 




O -N 
CNi r^ 


NO 00 

4 4 


<N '^ O M NO 

ro CO •^ On '^ 
VO VO NO no' 1>. 


q^ 


VO 

00 


On VO 00 

up NO r^ 

On d pi 

M M 






M 


M ON 

On rp 


t^ VO 

CO ro 
CS CO 


ro O 
00 CO 
CO 4 


On NO 't C^ O 

■4 VO VO NO NO 




8.6i 
9-57 
11.49 


N 


O 

00 


00 
01 

H 


O ro 
M c5 


l;^^ 

cs ci 


O ro 
CO CO 


NO 00 O ro NO 00 
(N NO M VO On ro 
tJ- Tt VO VO VO no" 


o 

CO 

NO 


VO O <N 

^. "? d 

t^ 00 H 


r 






M IH 


?0 


00 VO 

On ro 
(N ro 


CN| On NO ro H 
t^ O -^00 CI 
ro '^ '^ 4 u^ 


oo 

VO 
VO 


NO M VO '^ 

On i>. Tt On 
VO no" t^ oo' 


HiN 


O 


i 


^J nB 

l-l M 


M ro 
On N 


VO t^ 

VO 00 


On M fo ■* NO 

M lO 00 M rt 

ro CO ro -4 -^ 


00 

4 


o 

H 


rh 00 ir^ 
t^ ro vq 

VO NO !>. 


rtoo 


00 


CO 

00 


t- NO 


VO VO 

i>- q 


'* ro 

ro NO 


N <N On 
On <N up 00 q 

<N ro ro ro 4 


00 

rp 

4 


? 

4 


cT oq' q 

VO VO t>. 


i: 


o 

to 


o 

t-. O rp 


On no 
up CO 

M M 


ro On NO c^ On VO N 
H CO NO On M ■r}- t^ 

C^ c5 oi ci ro ro ro 


ro 


VO 
PI 

4 


00 . . 

TJ- 


1? 


O oo 


00 

lo O 

On N 

i-i 


Tt NO 


H VO 

On m 
M pi 


On ro NO H Ti- 
ro NO 00 M rp 
pj cJ C^ ro CO 


On 
VO 

ro 


00 

ro 


: : : 


H 




On 


lO NO 

00 q 


M M 


M 

X^ On 


P^ Tt lO NO 00 
M ro VO t^ On 
P^ (N CN pI <N 


On 
CO 


• 


: : : 


H« 




00 


rO On 
r^ On 


<N 

M rp 


On !>. NO -"^ ro H 

Tj- NO 00 O M "* . 

M M H c5 N (N 


• 


• 


: : : 


- 


o 


o 

00 


^ 8 

NO 00 


In ^ 


00 ^ 


O NO . . . 

NO j>. . . : 


: 


: 


: : ; 


KiX 




On 


ro VO 00 M 
ro NO On fO 
VO NO t^ On 


q S 












• 


• 


. . . 


r^ 




O 
cp 


lO M 

(M ro 
rj- up 


00 ^ 

NO !>. 


: : 


: : : : : 


: 


: 


: : : 




H«i 


"i 


H^ u^ 


«|oo t-^ 


■*» °^i:^ "*« ^H "H- "1:^ -^ ::^ 


r-i|ao ihHi Hn 

M M M H 



WEIGHTS OF SEAMLESS BRASS TUBING 



419 



1 






ro CO M 
10 ICO M Th rOOO 00 VO r^OO M TtOO Tt t-. OS n M rfO m 
r-- '^ On up M 00 CO OvO C| On !>. ro q 00 MD rt CS q 00 00 r^O lO to 
\OOiOlOtO'^'rl-rorOco<NC^pi(NMMMMiH 


- 


<>.00 M C^ t^ 

00 t^roc^ roOoO O t^OO OnOn^m loO O m O ^ rot^O «J~. 
00 lOCSQC tO<N t^iOM Onm ooOoOO --^-rOM OnOO t^O m lO '^ 


V 


loO r^oo O- 
rO OOOOO OnOoO C^ lom t-«f^M m OO ^tO roOsrOioOsroO 
OOO •^MOOO cs O t^voiN OOOO TtP< M O\00 \0 O u-i '^ T)- r^. 


'** 


O ro N 0\vO 'd- r^ •* C^ N M O VOVO 0\r>.t^N H Os-^t^-CS r^rf 
M o r^Ti-c^ o r^uocon Os«>-ioroiH Onoo r^ lo lo -^ ■^ co f^. 


H« 


O vO T)- 0) u-, 
OOOOO O^OO rot^ON'^t^ror^N O^OnO r^OO On to On lO m OO 
W M On I>~\0 ^<N 000^^^O'v^<N h OnOO COO lO^'^rOfOrOC^ 


M 


t^ to M OnO 
(N to 04 O OnOO m 0\nO tON IN Ooor^O '^ ■*vO On to M CO ^0) 
■^roN M OnCO t^iOTfroW M Ooqr^ r-.vO torJ-rorOCTJC^ C^_ f^ 
(NC^<Nc5mmmmmmmmih 


H« 


to to o t^ Onoo r^ ^ 0\ n to moo i>- 

. . too 00 00 •* to too too too O O '^O O roMt^Tj-(H On 
. . 00 t^NO to -^ ro C^ w q OnOO l^NO ^. ^ 't t ""? ^7 *^. '^. '^. '^. 


COW 


COJ>-0 •^lOrot^rO OnO CO OnO On 

, . . On On H rfO t^ O m ^O m O On TfOO O ro O CO O 

N M H O OnOO 00 t^O totO'sJ-COCOCN N CS <N H M 

H H H M 


>oi« 


OOOMOOtoOiooONO^coTfO 

O O t^ (N t^ O tOOO <NNO (NOO <NCO COM ONt^tOTt- 

..... q qM>D oq i>- i>-no ^ ^ "^t "t "7 ^ *^. '^. *^. '^ ". "^ 1 


»5 


O'^OONlNOOMtN'st-O'^tO t^O 

• • • • • • » t^ M to H t^ (H O O t^ CO On to M On t^ to co C^ 

• ' • . . • • t^ t^O OtOtO"*-<^'cocoC^ N N M H M M M 




H« 


M to O too totOMOO COC^O M O 
. . . . . . .TtMOOCOON'*Oto<NONiOC>)OOr^torO<NtH 

OO tOtO-TfTf'^COCON n Ol M M M M M IH 


^ 


cot^O coONtoO cocOM coOn t^O 
n OnO com t^rJ-O t^toN OnO to CO m O On 

tO-^'^'Tj-'^COCOCOC^ CN) W M M M M M H O 


e*o 


TtOOM(NC^COMOOOC^nOM 

« O OnOO no coOCOtocoMOOO coCN m O OnOO 

TtCOCOCOCOCO(N<NC^C^MIHMMIHJ-lOO 




O t~-0 mO OnO O co^coO< rtcO 
Otoro<NOoOOtocoMO OnOO I>-nO 






^. 


t^O O ^XCO CO MO M c^OOO 01 
00 t^ f--0 ^ CO CS M O 00 00 t-^O to to 

• • ^ •-: ^. ". -: ". "1 "1 '1 °. o o. 9 o. o. 




O 01 t^oO O 0) t^ M r^ 04 On 


"5 


• • • q q q q q q q q q q q^ 


-« 


to '^ CO O O r^ M ONO •* 

• • • " 'l-TfrtTfcOcocoOlOIOl 

q q q q q q q q q q 


is 


O rl- OnCO O CO O toco ■* O On to CO 04 lOOO On04 tO0400 tool O 
OOO tocoOl 0030 •^COOI O ONOO f^O tO'^TtcocOOl 01 01 04 
r0040404MC4MMMMMMOOOOOOOOOOOOO 


^0 


H W CO '^J- too t^OO On O M 04 CO Tt too t^OO On O M 04 ro rj- lo 

„MMMMMMMMMWO4O10404Ol 



I 






HORSE-POWER, BELTS AND SHAFTING 



Horse-Power 

. Horse-power is an arbitrary unit of measurement which has been 
adopted for measuring the work of engines or machines. It is given 
as 33,000 foot pounds per minute which means i pound Hfted 33,000 
feet per minute or 33,000 pounds Hfted i foot per minute or 330 
pounds lifted 100 feet per minute, or any combination which gives 
33,000 foot pounds per minute. 



Steam Engine Horse-Power 

In a steam engine it means the effective steam pressure per square 
inch, times the length of piston movement per revolution in feet, 
times the piston area in square inches, times the number of revolu- 
tions per minute, and all divided by 33,000. This is easily remem- 
bered by the formula 

PLAN 



where 



33000 

P = mean effective pressure per square inch. 
L = length of a double stroke in feet. 
A = area of piston in square inches. 
N = number of revolutions per minute. 



Electrical Power 

As compared with electrical units the mechanical horse-power 
equals 746 watts or nearly f of a kilowatt. So that a kilowatt (1000 
watts) equals 1.34 horse power. 



Gas Engine Horse-Power 

The A. L. A. M. rating for gasoline engines, which means the rat- 
ing adopted by the American Licensed Automobile Manufacturers, is 
based on the assumption that the piston speed is 1000 feet per minute 
in all cases. This gives 1500 revolutions per minute for a 4-inch 
stroke motor, which is about average practice. Since the defeat of 
the Selden patent the A. L. A. M. has ceased to exist and this is now 
known as the S. A. E. standard (Society of Automobile Engineers). 

420 



AUTOMOBILE MOTOR HORSE-POWER 



421 



S. A. E. (A. L. A. M.) HORSE-POWER RATING 

D^ X N 

The formula adopted is and based on 1000 feet per min- 

2-5 
ute piston speed. D is the cylinder bore, N the number of cylinders, 
and 2.5 a constant, based on the average view of the Mechanical 
Branch as to a fair conservative rating. 

Table or Horse-Power for Usual Sizes of Motors, Based on 
S. A. E. (A. L. A. M.) Formula 



B02.E 


Horse-Power 


Ins. 


M/M 


I Cyl. 


2 Cyls. 


4 Cyls. 


6 Cyls. 


2| 


64 


2i 


5 


10 


15 


2I 


68 


2f 


5^ 


II 


I6i 


2j 


70 


3, 


6 


I2tV 


l8i 


2I 


73 


3t6 


6f 


I3I 


19I 


3 


76 


^l 


73- 


I4I 


2if 


3i 


79 


3H 


7-f 


i5f 


23T6 


3j 


83 


4i 


82 


16/0 


25I 


3f 


85 


41^6 


9l 


i8i 


27f 


4 


89 


4t^o 


9* 
10^ 


i9f 


^9^ 


31 


92 


4 


20i 


3if 


4 


95 


5f 


III 


22i 


33I 


3I 


99 


6 


12 


24 


36tV 


4 


102 


6f 


I2|- 
13! 


25f 


38I 


4l 


105 


6H 


27i 


40t^o 


4i 


108 


7i 


I4I 


28A 


43f 


4f 


III 


7f 


15 l¥ 


3of 


45if 


42 


114 


8to 


i6i 


32f 


48I 


4- 


118 


8x6 


i7i 


34i 


5if 


4t 


121 


9^ 


18 


36tV 


•54tV 


4l 


124 


9I 


19 


38 


57 


5 


127 


10 


20 


40 


60 


5i 


130 


io| 


21 


42 


63 


si 


^33 


II 


22 


44x0 


66i 


5f 


^37 


11^ 


23 


46 


69tV 


4 


140 


I2,V 
I2f 


'H 


48f 


72f 


5f 


143 


25-^ 


50I 


75-t 


5f 


146 


'4, 


262 


53 


792 


5l 


149 


i3if 


278 


55i 


82^ 


6 


^52 


i4i 


28t 


57l 


86f 



To simplify reading of the above, the horse-power figures are 
approximate, but correct within vne-sixteenth. 



422 HORSE-POWER, BELTS AND SHAFTING 



DRIVING POWER OF LEATHER BELTS 

The question of the proper size of a leather belt for a given power 
transmission resolves itself into a question of selecting various fac- 
tors. These factors have been worked out by experiments, by ana- 
lytical methods, and in practice. 

The horse-power that a belt will transmit depends upon the effective 
tension and the belt speed. The effective tension depends upon 
the difference in the tensions of the two sides of the belt and on 
the surface friction, which depends upon the ratio of the tensions 
and the angle of belt contact with pulley. 

Experiments and practice have shown that a belt of single thick- 
ness will stand a stress of 60 pounds per inch of width and give good 
results, that is, it will only require an occasional taking up and will 
have a fairly long life. The corresponding ^'alues for double and 
triple belts are 105 and 150 pounds per inch of width provided the 
pulleys are not too small. 

Experiments have sho\\Ti that on small pulleys the ratio of the 
tensions should not exceed 2, on medium pulleys 2.5, and on large 
pulleys 3. The larger the pulley, the better the contact; also the 
thinner the belt, the better the contact for the same size of pulley. 
When the pulley diameter in feet is three times the thickness of the 
belt in inches, or in this proportion, wx get equivalent results for 
different thicknesses of belts. This gives us a method of classifying 
our pulleys. The belt has to adjust itself in passing over a pulley 
due to its own thickness. Some adjustment is also necessary on 
account of the crowning of the pulley. These adjustments account 
for the different ratios for the various pulley diameters. The effects 
of the crown and pulley diameters are not usually considered in belt 
rules, although they should be. The ratios given are for 180 degrees 
wrap and decrease with less contact. 

The creep of the belt depends upon its elasticity and the load, 
and experiments have shown that this should not. exceed i percent, 
in good practice. In order to keep this creep below i per cent, it 
is necessary to limit the difference of tension per inch of width 6f 
single belt to 40 pounds. The corresponding values for double and 
triple belts are 70 and 100 pounds per inch of width. These figures 
are based on an average value of 20,000 for the running modulus of 
elasticity of leather belting. 

Table i has been prepared" on the basis of these limitations and 
gives a value for the factor or constant F in the equation 

H.P. = y^orW=^i^ 

in which F P is the horse_-power, V the belt velocity in feet per minute, 
and W the width in inches. 

Table 2 gives corrected values for F, when the arc of contact or 
wrap is greater or less than 180 degrees. On large pulleys the 
creep may exceed i per cent, if the wrap is over 180 degrees, as 
the increased friction gives a greater difference of tensions. 

To illustrate the use of the tables, we will take the followmg 
examples: 



FACTORS FOR BELT POWER 



423 



O ^ 


















00 



o o 
OS q 

O O d ro O 

fO O 10 



c^ O 
o d «N o 



O »o O <N O 



O O O ro 10 

r- f^ O 




On O 

00 10 

o vo d <N o 

ON 



a (U « .r^ 



C O 



.2-i 



2 S3 .„ .. 






8^8 

rj" cs M 


ro 

00 r^MD 


10 -^ Tt 


CO 


000 

fO !>- rO 
ro M 

HUM 




000 

10 ^ Tj- 




M 


t^ 00 

<N M ON 


000 

CO POO 


CN) 10 

10 ';^ -si- 


10 


<N On 

M M 


fO 


LO Tf ro 


M 


M c^oo 

M 


000 

10 10 


c§2n§ 

^ ^ ro 


R 


w a^oo 


000 

LO ^ O^ 

10 Tt 


000 

VO On "* 
Tt fo fO 


°i 


000 

(N CT) 

H QnOO 


nO 10 '^ 


000 

■Ti- t^ ro 
^ CO ro 


\ 


O'oo 00 


000 
M »o 

NO lO Tl- 


000 
Tt CO ro 


\ 


^5R 

00 t^ 


8n^^ 


2 ^2 

^ ro CO 




000 

00 t^ 


t^ t-- ro 
10 ^ rt- 


8^8 

Tt CO CO 


CM 
CM 


000 


N^Ngg 

*0 't 't 


gNsa 

fO CO <N 



424 HORSE-POWER, BELTS AND SHAFTING 

How much horse-power will a 4-inch single belt transmit at a speed 
of 4600 feet per minute passing over a 12-inch pulley? The factor 
is 920, therefore, 

46^X4 = 20 H.P. 
920 
How wide should a belt be in order to transmit 50 horse-power 
at 2000 feet per minute on a 36-inch pulley? 

W= ^° X ^^° = 20.7-inch single belt. 
2000 

This gives a \\adth of single belt beyond the usual limit, 8 inches 
being considered good practice for the maximum width of a single belt. 

W =-5£_>li^ ^ i^-inch double belt. 
2000 
How wide should a single belt be in order to transmit 2 horse- 
power at 600 feet per minute over a 4-in. puUey ^vith 140 deg. wrap? 
In this case we take the factor iioo from Table i and in Table 2 
find a corrected value for iioo under 140 degrees of 1270. 

W = — - — — = 4.2 $-inch single belt. 
000 

How wide a belt is required for 300 horse-power at 2000 feet per 

minute over a io-fo6t pulley? 

W = — = 70.5-inch double belt. 

2000 

This is too wide. Good practice calls for a change to triple at 

48 inches unless for some special reason a narrower belt is necessary. 

lY = ^°° X ^^° = 4g.s-inch triple belt. 
2000 

The results given by these factors are well within working values 
and the belts wiU probably transmit 50 per cent, more power than 
these factors, but at the expense of the life of the belt. A liberal 
allowance at the beginning means less annoyance, fewer delays in 
taking up the belts, longer life and less cost for renewals and repairs. 
Belt speeds of 4000 to 4800 ft. should rarely be exceeded. 

Transmission of power in miU work is by gearing, by shafting, 
by electric motors, and by leather and rope belting, and which of 
these should be used in a particular case is a problem for the engineer 
in charge to determine. 

For successful v/ork the pulleys must be large in diameter and 
must have a smooth surface where the rope bears upon them. The 
speed and the load on the rope must also be such as experience has 
shown to be economical. When these conditions are fulfilled, a 
rope drive is a very satisfactory method of transmitting power. 

The table shows the horse-power of driving ropes and the diameter 
of pulleys that should be used for this purpose. This table takes 
into consideration the effects of the centrifugal force, so that the 
strain on the rope is constant on the driving side in transmitting the 
tabular power, no matter what the speed may be. While many 
engineers recommend a much larger horse-power, we beheve the 
estimates here given are advisable except in temporary installations. 



DATA OF MANILA ROPE 

Horse-Power oe Manila Rope 



425 



Dia. 

of 

Rope 








Velocity, Feet per Minute 








I, COO 


1,500 


2,000 


2,500 


3,000 


3,500 


4,000 


4,500 


5, 000 


5,500 


6,000 


3 

4 


2.3 


3-3 


4-3 


5-2 


6.0 


6.6 


7.2 


7-3 


7.4 


7.3 


6.9 


i 


3-0 


4-5 


5-9 


7.0 


8.2 


9.0 


9.6 


9.8 


lO.O 


9.6 


9.0 




4.0 


5-9 


7-7 


9.2 


10.6 


11.8 


12.7 


12.9 


13.0 


12.7 


12.0 


'! 


5-0 


7.5 


9-7 


II.6 


13-5 


14.9 


16.0 


16.3 


16.7 


16.5 


15-3 


t1 


^•3 


9.1 


12.0 


14-3 


ib.7 


18.5 


20.0 


20.2 


20.7 


20.1 


18.9 


li 


7-5 


10.8 


14.4 


17.4 


20.0 


22.1 


23-7 


24-5 


24.6 


24.0 


22.3 


1^ 


9.0 


13-5 


17.4 


20.7 


23.0 


26.3 


28.7 


29.0 


29.5 


28.6 


26.7 


if 


10.5 


15-5 


20.1 


24-3 


27.9 


30.8 


32.9 


34-1 


34.3 


33-3 


31.0 


if 


12.3 


18.0 


23.6 


28.2 


32.7 


36.4 


38.5 


39-4 


40.5 


3«.7 


36.0 


2 


16.0 


23.2 


30.6 


46.8 


42.5 


46.7 


50.0 


51-7 


52.8 


50.6 


47-3 


2i 


20.0 


29.6 


38.6 


46.6 


53.6 


59.2 


63.6 


6=;.8 


66.3 


64.4 


60.3 


2^ 


25.0 


36.6 


47-7 


57-5 


66.0 


71.2 


78.0 


80.0 


81.0 


79.0 


73-8 



Data of Manila Transmission Rope 







^ 




S 


Length of SpUce, 






1 


e 
.2 

Q 
"o 




•5 
a 

en 


i 

< 




Feet 




•sj 

il 

J,1 


h 


"0 


1 


2 


1 


So.S 


.2 
Q 


3 


1 

< 




r 


CO 


w 
't 




gCAl 


rt a 


1 


•5625 


.20 


3,950 


112 


6 


8 




28 


760 


i 


.7656 


.26 


5,400 


153 


6 


« 




32 


650 




I. 


•34 


7,000 


200 


7 


10 


14 


36 


570 


li 


1.2656 


.43 


8,900 


253 


7 


10 


16 


40 


510 


U 


1.5625 


•53 


10,900 


312 


7 


10 


16 


46 


460 




1.8906 


•65 


13,200 


378 


8 


12 


16 


50 


415 




2.25 


•77 


15,700 


450 


8 


12 


18 


54 


380 


if 


2.6406 


.90 


18,500 


528 


8 


12 


18 


6o- 


344 


^4 


3.0625 


1.04 


21,400 


612 


8 


12 


18 


64 


330 


2 


4- 


1.36 


28,000 


800 


9 


14 


20 


72 


290 


24 


5-0625 


1-73 


35,400 


1,012 


9 


14 


20 


82 


255 


2^ 


6.25 


2.13 


43,700 


1,250 


10 


16 


22 


90 


230 



Weight of transmission rope = .34 X diameter.^ 

Breaking strength = 7,000 X diameter.^ 

Maximum allowable tension . = 200 X diameter.^ 

Diameter smallest practicable sheave. . = 36 X diameter. 

Velocity of rope (assumed) = 5,400 feet per minute. 



426 HORSE-POWER, BELTS AND SHAFTING 



BELT FASTENINGS 

The best fastening for a belt is the cement splice. It is far 
beyond any form of lacing, belt hooks, riveting, or any other 
method of joining together the ends of a belt. The cement joint is 
easily applied to leather and to rubber belts, but to make a good 
cement splice in a canvas belt requires more time and apparatus 
than is usually at hand. Good glue makes a fine cement for leather 
belts, and fish glue is less affected "by moisture than the other. 
Many of the liquid glues are. fish glue treated with acid so as not 
to gelatinize when cold. A little bichromate of potash added to 
ordinary hot glue just before it is used will render it insoluble in 
water. Both lap and wedge joints are used. 

Belt Hooks 

There are many styles of belt hooks in use, some of the more com- 
mon kind being shown in Figs, i, 2, 3 and 4. Fig. 2 is practically 
a double rivet, Fig. 3 a malleable iron fastening, although similar 
hooks have been made of pressed steel, and Fig. 4 is the Blake stud, 
which has the advantage of not weakening the belt but makes a 
hump on the outside where the ends turn up. Fig. 5 is the Bristol 
hook of stamped steel which is driven in the points turned over on 
the other side. Fig. 6 is the Jackson belt lacing and is applied 
by a hand macliine which screws a spiral wire across the ends of a 
belt. These are then flattened and a rawhide pin or a heavy soft 
cord used as a hinge joint between them. These joints are probably 
equal to 90 per cent, of the belt strength. 

Lacing Belts 

Belts fastened by lacing are weakened according to the amount 
of material punched out in making the holes to receive the lacing. 
It is preferable to lace with a small lacing put many times, through 
small holes. Such a joint is stronger than a few pieces of wide lacing 
through a number of large holes. Figs. 7 and 9 illustrate two forms 
of belt lacing, the latter being far preferable to the other. The lacing 
shown by Fig. 7 is in a double leather belt 5 inches wide. The width 
makes no difference as the strength is figured in percentage of the 
total width. There are four holes in this piece of belt, each hole 
f inch in diameter. The aggregate width thus cut out of the belt is 
4Xf inch=-^/ = i^- inches. Then 1.5 -=-5 =0.30, or 30 per 
cent, of the belt has been cut away — ^nearly one-third of the total 
strength. 

Another Method of Lacjng 

In Fig. 9 a different method is followed. Instead of there being a 
few large holes, there are more smaller ones — one fourth more, in 
fact. There are five holes, each j\ inch in diameter, making a 
total of If inch or 0.9375 -r S = i8f per cent., leaving SiJ per 
cent, of the total belt strength against 70 per cent, in the belt with 
large holes. A first-class double leather belt will tear in two under 



BELT HOOKS AND LACINGS 



427 



a strain of about 500 pounds to each lace hole, the strain being 
applied in the holes by means of lacings. 

The belt shown by Fig. 9 has 81-4- per cent, of 1.875 square inches 
of section, = 1.525 square inches left after cutting out the five holes. 
This amount is good for 3000 X 1.875 = 5625 pounds breaking 
strain, and as the lacing will tear out under 2500 pounds, it will be 
seen that we cannot afford to use lacings if the full power of the 
leather is to be utilized. This, under a factor of safety of 5, would 
be 1 1 25 pounds to the square inch, or 11 25 X 1-525 = 1715 pounds 



e:=^ 



FIG. I 




PI.Gv 8 FIG. 9 

Belt Hooks and Lacings 



working strain for the belt, ori7i5-7-5=343.5 pounds to each 
lace. This, too, is too much, as it is less than a factor of safety of 2. 

The belt to carry 40 pounds working tension to the inch of width 
must also carry about 40 pounds standing tension, making a strain 
of 80 pounds to the inch, or 80 X 5 = 400 pounds. This is a better 
showing, and gives a factor of safety of 2500 -r- 400 = 6J. Still, we 
are wasting a belt of 5625 pounds ultimate strength in order to get 
from it 400 pounds working strain. This means a factor of safety 
of over 14 in the body of the belt but of only 6^ at the lacing, which 
shows the advantage of a cement splice. 

Fig. 10 shows a method sometimes used t© relieve the lace-holes 
of some of the strain. Double rows of holes are punched as at o &, 
and the lacing distributed among them. As far as helping the 



428 



HORSE-POWER, BELTS AND SHAFTING 



strength of the belt is concerned, this does nothing, for all the stress 
put upon the belt by the lacing at c must be carried by the belt sec- 
tion at a; therefore this way of punching holes does not increase the 
section strength. Neither does staggering the holes as shown at d 
and e. The form of hole-punching shown at a & c is desirable for 
another reason. It distributes the lacing very nicely and does not 
make such a lump to thump when it passes over the pulleys. 

ALINING SHAFTING BY A STEEL WIRE 

A STEEL wire is often used for ahning shafting by stretching it 
parallel with the direction of the shaft and measuring from the shaft 
to the wire in a horizontal direction. This steel wire can also be 
used for leveling or alining in a direction at right angles to the other, 

Sags of a Steel Alining Wire for Shafting 

Distance in Feet, from Reel to Point of Measurement 



3° 



40 



50 



60 



70 



90 



130 



140 





270 


*. 


260 


SL 


2=;o 


^ 
^ 


240 


230 




220 






.9 


210 


^ 


200 


2 


190 


-s 


tSo 






Pi 


170 


s 


160 


ii 


150 


"S 


140 


k 


130 


fl 


120 








no 








100 






"C 


90 


(-) 


80 




70 




60 




so 




40 




30 



If 



itV 



t13 
I32 

iM 

T 9 

I 3" 2 



III 
iH 

I32 

itV 



■••3 2 

it\ 

13^ 

'ft 
53 
64 

If 
f 
if 



ill 
iH 

IT6 

itV 

'ft 

13 

tb; 

45 

fi4 



t13 

lii 

1*1- 



lT6 

ItV 

i\ 

5 3 
23 

it 



ifl 

Its 



■■■3 2 
I ¥'2 

'If 

6¥ 
II 
II 
If 
I 
I 
6^ 



Sag of the Wire in Inches 



SAGS OF A STEEL ALINING WIRE 



429 



by making vertical measurements, if it is stretched imder established 
conditions and if the sags at the points of measurement are known. 
The accompanying table gives the sags in inches from a truly level 
line passing through the points of support of the wire, at successive 
points beginning 10 feet from the reel and spaced 10 feet apart for 
a No. 17 Birmingham gage high grade piano wire, stretched with a 
weight of 60 pounds, wound on a reel of a minimum diameter of 
three and one-half inches and for total distances between the reel 
and point of support of the wire varying by increments of 10 feet 
from 40 to 280 feet. Thus a wire of any convenient length, of the 
kind indicated, can be selected, so long as this length is a multiple 
of ID feet and between the limits specified, and the table gives the 
sags from a truly level line at points 10 feet apart for its entire length 
when it is stretched under the conditions designated. These sags 

Sags of a Steel Alining Wire for Shafting 



Distance in Feet, from Reel to Point of Measurement 



280 
270 
260 
250 
240 
230 
220 
210 
200 
190 
180 
170 
160 



ISO 



Iff 

l6¥ 

I32 
t13 
I32 

lif 

u 

H 
If 

13 
"32 



64 



[6c 



^64 
III 
I32 
l6\ 

u 



190 



T 1 O 
132 

lii 

ItV 



T-a-i 
l64 

iH 
1/4 

15 



230 240 



ItV 



250 



260 



if 



270 



Sag of the "Wire in Inches 



being known, direct measurements can be made to level or aline 
a shaft by vertical measurements. 

The method was originally developed for alining the propeller 
shafts of vessels, but it is equally serviceable for semi -flexible shafting, 
as factory line shafts. 



Speed of Shafting 

Line shaft speed varies with machinery it drives. Probably 250 
r.p.m. is an average today, with cases of 400 r. p. m. even on 4-in. shafts 
and 600 to 700 r. p. m. on 2-in. shafts for high speed machinery. 



430 



HORSE-POWER, BELTS AND SHAFTING 



HORSE POWER OF STEEL SHAFTING 

For Line Shapt Service 



^ 








Revolutions per 


Minute 








^.^ 


^ 'S> 






















III 




lOO 


125 


150 


17s 


200 


225 


250 


300 


350 


400 


It\ 


2.4 


3-1 


3-7 


4-3 


4.9 


5-5 


6.1 


7-3 


8-5 


9-7 




It'b 


4-3 


5-3 


6.4 


7-4 


«-5 


9-5 


10.5 


12.7 


14.8 


16.9 


6.8" 


H 


0.7 


8.4 


lO.I 


II. 7 


13-4 


15-I 


16.7 


20.1 


23-4 


26.8 


7-2" 


i\% 


lO.O 


12.5 


15-0 


17.5 


20.0 


22.5 


25-0 


30.0 


35-0 


40.0 


8.2" 


2 fa 


14-,^ 


17.8 


21.4 


24.9 


28.5 


32.1 


35-6 


42.7 


49-8 


57.0 


8.9" 


2th 


iq.5 


24.4 


29-3 


ZA.X 


39-0 


44-1 


48.7 


5«-5 


68.2 


78.0 


9.6" 


2U 


26.0 


32.5 


39-0 


43-5 


52.0 


5«-S 


65.0 


78.0 


87-0 


104.0 


10.2" 


2iii 


,S,V8 


42.2 


50.6 


S9-I 


67-5 


75-9 


84.4 


101.3 


118.2 


135.0 


10.8" 


3t'« 


4.^-o 


,S3.6 


64.4 


7S-I 


85.8 


96.6 


107.3 


128.7 


150.3 


171. 6 


1 1. 4* 


M'-. 


S.Vb 


67.0 


79-4 


93-8 


107.2 


120. 1 


•T34-0 


158.8 


187-6 


214.4 


12.0" 


■>\k 


65-9 


82.4 


97-9 


iiS-4 


121.8 


148.3 


16^.8 


195-7 


230.7 


243.6 


12.5" 


Mi 


80.0 


lOO.O 


120.0 


140.0 


160.0 


iSo.o 


200.0 


240.0 


280.0 


320.0 




4T'n 


113-9 


142.4 


170.8 


199-3 


227.8 


256.2 


284.7 


341-7 


398.6 


. 455.6 






4ls 


I,S6.,S 


195-3 


•234-4 


273-4 


312-5 


351-5 


390.6 


468.7 


546.8 


625.0 






5l 


207.9 


260.0 


311-9 


363-9 


415-9 


459-9 


520.0 


623.9 


727.9 


830.0 









270.0 


337-5 


405-0 


472-5 


540.0 


607.5 


675-0 


810.0 


945-0 


1080.0 






bi 


,U3.3 


429.0 


514-9 


600.7 


6S6.5 


772.4 


858.0 


1029. 


1201.0 


1372.0 






7 


428.8 


535-9 


643-1 


750.3 


847-5 


964-7 


1071-9 


1286.0 


1500.0 


1695-0 






8 


640.0 


Soo.o 


960.0 


1126.0 


12S0.0 


1440.0 


1600.9 


1920.0 


2240.0 


2560.0 







This table is based on the formula 



M 



80 



For heavier work use M 



D^XR 



For head and jack shafts, supported by bearings close to main 
sheave or pulley so as to prevent transverse strain, the following 
formula may be used with safety: 

D'XR 



M = 



125 



D = Diameter of shaft in inches. 

R = Number of revolutions per minute. 

M = Horse-power. 
Deflection of shafting from weight of pulleys and draw of belting 
should not be allowed in excess of .001 per foot, as this action adds 
very rapidly to the power cost. If this deflection is at a clutch,- 
sleeve or roller bearing, any of them may be ruined easily and quickly. 
It can be reduced by using more hangers. 

SPEEDS OF PULLEYS AND GEARS 

The fact that the circumference of a pulley or gear is alwaj^s 
3.1416 or 37- times the diameter makes it easy to figure speeds by 
considering only the diameter of both driver and driven pulleys. 
Belting from one 6-inch pulley to another gives the same speed to 
both; but if the driving pulley is 16 inches and the driven pulley 
only four inches it is clear that the small pulley will turn 4 times for 



SPEEDS OF PULLEYS AND GEAHS 



431 



every turn of the large pulley. If this is reversed and the small 
pulley is the driver, the large pulley will only make one turn for 
every four of the small pulley. The same rule applies to gears if 
the pitch diameter and not the outside diameter is taken. The fol- 
lowing rules have been arranged for convenience in finding any 
desired information about pulley or gear speeds. 



Diameter of Driving Pulley 
Diameter of Driven Pulley 
Speed of Driving Pulley 



Diameter of Driving Pulley 
Speed of Driving PuUey 
Speed of Driven Pulley 



Diameter of Driving Pulley 
Diameter of Driven Pulley 
Speed of Driven Pulley 



Diameter of Driven Pulley 
Speed of Driven Pulley 
Speed of Driving Pulley 



Speed of Driven Pulley 



Diameter of Driven Pulley 



Speed of Driving Pulley 



Diameter of Driving Pulley 



Multiply Diameter of 
Driving Pulley by its 
Speed and divide by 
Diameter of Driven 
Pulley. 

Multiply Diameter of 
Driving Pulley by its 
Speed and Divide 
by Speed of Driven 
Pulley. 

Multiply Diameter of 
Driven Pulley by its 
Speed and Divide by 
Diameter of Driving 
Pulley. 

Multiply Diameter of 
Driven Pulley by its 
Speed and Divide 
by Speed of Driving 
Pulley. 



These rules apply equally well to a number of pulley belts to- 
gether or to a train of gears if all the driving and all the driven pulley 
diameters and speeds are grouped together. 

TABLES OF CIRCUMFERENTIAL SPEEDS 

The tables on pages 432-435 which give circumferential speeds, 
can be used for obtaining gear and belt speeds and the speed of 
revolving parts of high-speed motors. 

For diameters greater than those given in the tables, the speeds 
can be obtained by adding together the speeds for two diameters 
whose sum equals that of the diameter for which we require the 
speed. For example, to find the speed at a 120-inch diameter and 
200 revolutions per minute, the following calculation is readily made : 

Speed for 100-inch diameter — 5236 feet. 

Speed for 20-inch diameter — 1047 feet. 

Speed for 120-inch diameter — 6283 feet. 
To interpolate, we can use the values given for speed for i- to 
lo-inch diameters, dividing them by 10, 100, 1000, etc., to obtain 
speeds for tenths, hundredths, thousandths, etc. For instance, if 
the speed for 550 revolutions per minute and 46.186-inch diameter 
is required, we proceed as follows: 

For 46 in. diameter speed = 6623 ft. 

For 0.1 in. diameter = -^ of i-in. diameter speed = 14.4 ft. 

For 0.08 in. diameter = i^^ of 8-in. diameter speed = 11. 5 ft. 

For o.oo6 in. diameter = i^Vo of 6-in. diameter speed = . o.g ft. 

For 46.186 in. diameter speed = 6650 ft. 



432 



HORSE-POWER, BELTS AND SHAFTING 



Circumferential Speeds in Feet per Minute 
{See page 431) 







Revolutions per Minute 




50 


100 


150 


200 


250 


300 


350 


400 


450 


500 


S50 




I 


13 


26 


39 


52 


65 


79 


92 


los 


118 


131 


144 




2 


26 


52 


79 


105 


131 


157 


183 


209 


236 


262 


288 




3 


39 


79 


118 


157 


196 


236 


275 


3^4 


353 


393 


432 




4 


52 


los 


157 


209 


262 


314 


367 


419 


471 


523 


576 




5 


65 


131 


196 


262 


328 


393 


458 


524 


589 


654 


720 




6 


79 


157 


236 


314 


393 


471 


550 


628 


707 


785 


863 




7 


92 


183 


275 


367 


458 


55? 


641 


IH 


82s 


916 


1,008 




8 


105 


209 


314 


419 


524 


628 


733 


838 


942 


1,047 


1,152 




9 


118 


236 


353 


471 


589 


707 


82s 


942 


1,060 


1,178 


1,296 




10 


131 


262 


393 


524 


655 


785 


916 


1,047 


1,178 


1,309 


1,440 




II 


144 


288 


432 


576 


720 


864 


1008 


1,152 


1,296 


1,440 


1,584 




12 


157 


314 


471 


628 


785 


943 


IIOO 


1,257 


1,414 


1,571 


1,728 




13 


170 


340 


511 


681 


851 


1021 


1191 


1,361 


1,532 


1,701 


1,872 




14 


183 


367 


550 


733 


916 


IIOO 


1283 


1,466 


1,649 


1,832 


2,016 




IS 


196 


393 


589 


785 


982 


1178 


1375 


1,571 


1,767 


1,963 


2,160 




16 


209 


419 


628 


838 


1047 


1257 


1466 


1,675 


1, 88s 


2,094 


2,304 




17 


223 


445 


668 


890 


1113 


1335 


1558 


1,780 


2,003 


2,22s 


2,442 




18 


236 


471 


707 


943 


1178 


1414 


1649 


1,885 


2,121 


2,356 


2,592 




19 


249 


497 


746 


995 


1244 


1492 


1741 


1,990 


2,238 


2,487 


2;736 




20 


262 


524 


785 


1047 


1309 


1571 


1833 


2,094 


2,356 


2,618 


2,880 


1 


21 


275 


550 


825 


HOC 


1374 


1649 


1924 


2,199 


2,4 74 


2,749 


3,024 


22 


288 


576 


864 


II52 


1440 


1728 


2016 


2,304 


2,592 


2,880 


3,168 


1 


23 


301 


602 


903 


1204 


1505 


1806 


2107 


2,409 


2,710 


3,011 


3,312 




24 


314 


628 


943 


1257 


1571 


1885 


2199 


2,513 


2,827 


3,142 


3,456 


^c 


25 


327 


655 


982 


1309 


1636 


1963 


2291 


2,618 


2,945 


3,273 


3.600 


S 


26 


340 


681 


1021 


I36I 


1702 


2042 


2382 


2,723 


3,063 


3,403 


Hii 


^ 

V 


27 


353 


707 


1060 


I4I4 


1767 


2121 


2474 


2,827 


3,181 


Hl"^ 


3,888 


E 


28 


367 


733 


IIOO 


1466 


1837 


2199 


2566 


2,932 


3,299 


3,665 


4,032 


.2 


29 


380 


759 


II39 


I5I8 


1898 


2278 


2657 


3,037 


3,417 


3,796 


4,176 


s 


30 


393 


785 


II78 


I57I 


1964 


2356 


2749 


3,142 


^ 534 


S,02 7 


4,320 




31 


406 


812 


I2I7 


1623 


2029 


2435 


2840 


3,246 


3,652 


4,058 


4,464 




32 


419 


838 


1257 


1676 


2094 


2513 


2932 


3,351 


3,770 


4,189 


4,608 




33 


432 


864 


1296 


1728 


2160 


2592 


3024 


3,456 


3,888 


4,320 


4,752 




34 


445 


890 


1335 


1780 


2225 


2670 


3115 


3,560 


4,006 


4,451 


4,896 




35 


458 


916 


1375 


1833 


2291 


2749 


3206 


3,66s 


4,123 


4,581 


5,040 




36 


471 


943 


I4I4 


1885 


2356 


2827 


■3299 


3,770 


4,241 


4,712 


5,184 




37 


484 


969 


1453 


1937 


2422 


2906 


3390 


3,875 


4,359 


4,843 


5,328 




38 


497 


995 


1492 


1990 


2487 


2985 


3482 


3,979 


4,477 


4,974 


5,472 




39 


511 


1021 


1532 


2042 


2553 


3063 


3573 


4,084 


4,595 


5,105 


S,6i6 




40 


524 


1047 


I57I 


2094 


2618 


3142 


3665 


4,189 


4,712 


5,236 


5,760 




41 


537 


1073 


I6I0 


2147 


2683 


3220 


3757 


4,294 


4,831 


5,367 


5,904 




42 


550 


1 100 


1649 


2199 


2749 


3299 


3848 


4,398 


4,948 


5,498 


6,048 




43 


563 


1126 


1689 


2251 


2S14 


3377 


3940 


4,503 


5,066 


5,629 


6,192 




44 


576 


1152 


1728 


2304 


2880 


3456 


4032 


4,608 


5,184 


5,760 


6,336 




45 


589 


1178 


1767 


2356 


2945 


3534 


4123 


4,712 


5,301 


5,891 


6,480 




46 


602 


1204 


1806 


2408 


3011 


3613 


4215 


4,817 


5,419 


6,021 


^^3§ 




47 


615 


1231 


1846 


2461 


3076 


3692 


4307 


4,922 


5,537 


6,152 


6,768 




48 


628 


1257 


1885 


2513 


3142 


3770 


4398 


5,027 


5,655 


6,283 


6,912 




49 


641 


1283 


1924 


2566 


3207 


3849 


4490 


5,131 


5,773 


6,414 


7,056 




50 


65s 


1309 


1963 


2618 


3273 


3927 


4581 


5,236 


5,891 


6,545 


7,200 



TABLES OF CIRCUMFERENTIAL SPEEDS 



433 



CmCUMTERENTIAL SPEEDS IN FeET PER MiNUTE 

(See page 431) 











Revolutions per 


Minute 










50 


100 


150 


200 


250 


300 


350 


400 


450 


500 


550 




51 


668 


1335 


2003 


2670 


3338 


4006 


4673 


5,341 


6,008 


6.676 


7,343 




52 


681 


1361 


2042 


2723 


3403 


4084 


4764 


5,445 


6,126 


6,807 


7,487 




53 


694 


1388 


2o8t 


2775 


3469 


4163 


4856 


5,550 


6,244 


6,938 


7,631 




54 


707 


1414 


2I2I 


2827 


3534 


4241 


4948 


5,655 


6,362 


7,069 


7,775 




55 


720 


1440 


2160 


2880 


3600 


4320 


5040 


5,760 


6,480 


7,199 


7,919 




56 


733 


1466 


2199 


2932 


3665 


4398 


5131 


5,864 


6,597 


7,330 


8,063 




57 


746 


T492 


2238 


2985 


3731 


■4477 


5223 


5,969 


6,715 


7,461 


8,207 




58 


759 


1518 


2278 


3037 


3796 


4555 


5314 


6,074 


6,833 


7,592 


8,351 




59 


772 


1545 


2317 


3089 


3862 


4634 


5406 


6,178 


6,951 


7,723 


8,495 




60 


785 


1571 


2356 


3142 


3927 


4712 


5498 


6,283 


7,069 


7,854 


8,639 




61 


799 


1597 


2395 


3194 


3992 


4791 


5589 


6,388 


7,186 


7,985 


8,783 




62 


812 


1623 


2435 


3246 


4058 


4870 


5681 


6,493 


7,304 


8,116 


8,927 




63 


825 


1649 


2474 


3299 


4123 


494» 


5773 


6,597 


7,422 


8,247 


9,071 




64 


838 


1676 


2513 


3351 


4189 


5027 


5864 


6,702 


7,540 


8,378 


9,215 




05 


851 


1702 


2552 


3403 


4254 


5105 


5956 


6,807 


7,658 


8,508 


9,359 




66 


864 


1728 


2592 


3456 


4320 


5184 


6048 


6,912 


7,775 


8,640 


9,503 




67 


877 


1754 


2631 


3508 


4385 


5262 


6139 


7,016 


7,893 


8,770 


9,647 




68 


890 


1780 


2670 


3560 


4451 


5341 


6231 


7,121 


8,011 


8,901 


9,791 




69 


903 


1806 


2710 


3613 


4516 


5419 


6322 


7,226 


8,129 


9,032 


9,935 




,0 


.916 


1833 


2749 


366s 


4581 


5498 


6414 


7,330 


8,247 


9,163 


10,079 




71 


929 


I8S9 


2788 


3718 


4647 


5576 


6506 


7,435 


8,365 


9,29! 


10,223 


'Q 


72 


943 


1885 


2827 


3770 


4712 


5655 


6597 


7,540 


8,482 


9,425 


10,367 


-s 


73 


956 


1911 


2867 


3822 


4778 


5733 


6689 


7,644 


8,600 


9,556 


10,511 


c 


74 


969 


1937 


2906 


3875 


4843 


5812 


6781 


7,749 


8,718 


9,687 


10,655 
10,796 


C3 


75 


982 


1964 


2945 


3927 


4909 


5890 


6872 


7,854 


8,836 


9,818 




76 


995 


1990 


2985 


3979 


4974 


5969 


6964 


7,959 


8,954 


9,948 


10,943 


1 


77 


1008 


2016 


3024 


4032 


5040 


6048 


7056 


8,063 


9,072 


10,079 


11,087 




78 


1021 


2042 


3063 


4084 


5105 


6126 


7147 


8,168 


9,189 


10,210 


11,231 


79 


1034 


2068 


3102 


4136 


5171 


620s 


7239 


8,273 


9,307 


10,341 


11,375 


P 


80 


1047 


2094 


3142 


4189 


5236 


6283 


7330 


8,378 


9,425 


10,472 


11,519 




81 


1060 


2121 


3181 


4241 


5301 


6362 


7422 


8,482 


9,543 


10,603 


11,663 




82 


1073 


2147 


3220 


4294 


5367 


6440 


7514 


8,587 


9,660 


10,734 


11,807 




83 


1087 


2173 


3259 


4346 


5432 


6519 


7605 


8,692 


9,778 


10,865 


11,951 




84 


1 100 


2199 


3299 


4398 


5498 


6597 


7697 


8,797 


9,896 


10,996 


12,099 




85 


1113 


2225 


3338 


4451 


5563 


6676 


7789 


8,901 


10,014 


11,127 


12,235 




86 


1126 


2251 


3377 


4503 


5629 


6754 


7880 


9,006 


10,132 


^^'^Vo 


12,383 




87 


1139 


2278 


3417 


4555 


5694 


6833 


7972 


9,111 


10,249 


11,388 


12,527 




88 


1152 


2304 


3456 


4607 


5760 


6912 


8063 


9,215 


10,367 


11,519 






89 


1161 


2330 


3495 


4660 


5825 


6990 


8155 


9,320 


10,485 


11,650 






90 


1178 


2356 


3534 


4712 


5891 


7069 


8247 


9,425 


10,603 


11,780 






91 


1191 


2382 


3574 


4765 


5956 


7147 


8338 


9,530 


10,721 


11,912 






92 


1204 


2408 


3613 


4817 


6021 


7226 


8430 


9,634 


10,839 


12,043 






93 


1217 


2435 


3652 


4870 


6087 


7304 


8522 


9,739 


10,956 


12,174 






94 


1231 


2461 


3692 


4922 


6152 


7383 


8613 


9,844 


11,074 


12,305 






95 


1244 


2487 


3731 


4974 


6217 


7461 


8704 


9,948 


11,192 


12,436 






96 


1257 


2513 


3770 


5027 


6283 


7540 


8796 


10,053 


11,310 


12,566 






97 


1270 


2539 


3809 


5079 


6349 


7618 


8888 


10,158 


11,428 








98 


1283 


2566 


3849 


5131 


6414 


7697 


8980 


10,263 


11,545 








99 


1296 


2592 


3888 


5183 


6480 


7775 


9071 


10,367 


11,663 








100 


1309 


2618 


3927 


5236 


6545 


7854 


9163 


10,472 


11,781 







434 



HORSE-POWER, BELTS AND SHAFTING 



00 t^^ lO ■N^ M M O OiOO vO vo ^ ro cs O OvOO t^^O ■* rO M 

c^ moo H '^t t^ o fo >^oo_ !-<„ ^ <"; 0_ ^"O 00 >-^ ^ t^ 0_ fo^o 

h" m" H cT «" M cs" c<l CO ^0 't ^ "i- -^ >J^ lO loo'vo"^ 



t^ Ov M M ^vO 00 O corO^Ot^Ow N "^VO 00 i 
^O r~.rOO>iOMOO •*0^ <^00 low t^ro 0>N 

•^ "^ 'O'^ 9- '^^^^ " "l!^_ '-5 ". 't ""; 9! ^ "^ ' 

m" H~ m" m" oT N ci N CO fO to fO ^ 't ■^ -^ »o VO 1 



0\ t^O to rj- o) i-i O 00 i^'O 'i- <o N M O\00 r^ vo •^ ! 
■rfOv^O^OvM-O tOOO <O00 rocc to t^ cs t^ <N r~ < 
tN •^t^Ocs ■^t^Ow rtt-^OtN Tl-r^O»<N rJ-r^Ot 



•oO •+0>iow\0 M r^toOi^OvO w r^MOO -^Oi- 
1" t^ M Tj-OO fJ voOiNO Oitot^O •"d-t^M "^-OO H 
^ M ^>o 00 w CO looo O tN "It"; 0_t^'*«-;0; '-<_'* 

M H p-T m" pT cT <N cT CO to CO to 'd- ■^ ■* •<? •* >o >o 



CO VOOO O CO »O00 O CO lOOO O CO lOOO O co^O 00 H covO 00 
IN -JO Ov w CO lOOO O tN ^ t-» O iH coo 00 O CM lO t^ O H 

<N ^OOO HCOlOl' .-- --. 



IN ^1 



M M M N Ci CO to I 



O OiOO 00 f~. t^vo »o lO 

O M M CO ^ vovO t^OO ^ , 

c^ 'to 00 o ts -^vo 00 o '^"2'^^'^'^"2'~;'^'^ '^'^°^ 

Hri-rh-Ti-ri-rcrMMtNw cococococo'^'t't'^ 



O coO>iONoOiOM r~-<tOO « 0>>0?)00 ^Mt^coOO 
0> OOO 00 00 t^ t^ t^O OO ioiO^-*-*cocOfO<~< M tN M 
M comt^-OiM coioi^OvM co>ot--.q;w_cotor^qiiHco>o 

MI-Tl-ri-rMci'c^'crtNMCOCOCOCOCO'^'t'* 



L^ 



CO (^ O coo O coo O^ coO O^MO 0\CJio0^w toOO CM lO 
OO ^ lOPOwOoOO -^cow OvOO O •* to H OOO O "t CO I-I 
w CO >o !>. Oi w tN "+0 00 O "-ItOior^qjwO)^ '^O 00__ 0_ c^^ 

i-Ti-TMHi-rorortNtNcrc^ tococococo^-ti- 

OOOlHI-ll-tWMMMNNCJCMtNCOCOCOCOCOCO**'^ 
J^ ■* w 00 »0 CM OvO coo t~--+HOO »OtN (^O CO O t- •* M 
M CO lOO 00 O iH CO »o r^GO O <M CO *o r^oo O m tj- lo t-; 0» 

(H^H'i-rM'i-ri-rcrci'crcM'tNorcocococococo 

r^rJ-H00iON0«^'ti-<00»OCM OvO co O t^ lo m OiO cO 

>OM t^tNOO •*0 >OW r~.CgOO TfOVOW t^CMOO tJ-QMOW 

M co-^Ot^Oi-i CM Ttio t^oO O M CO ioO^00_ O; w tM ^O 

MHHMMMtN'tNPrCMtN^erCM COCOCOCO 
M CM CO -+ lOO t^OO 0\ O W CM CO ■* VOO t^<» 0> O w " CO 



Hp< 


H 


rt|t< 


Clr 


CO CO 


rt"-^ loloO O 


rtIN wlc. H« HIN 

t~. t-00 00 Oi o* o o 


M M 


r^ 


Ho 


BW 


M W M W 


C< tN IN CM 


COCOtOCO'^tJ-^'t'O'"""^ 



saqouj ui aajauiBjQ 



TABLES OF CIRCUMFERENTIAL SPEEDS 



435 



t- t^oo oooooo O' S S o 6 o o 



lO'O O ^O O t^ t^ t^ r~00 OOOOOO OvOvO\0^0 O O O 



L 



vo Ov P) O Ov too O ^ t^ w Tt-OO H looO M \0 O rOO O <0 
>0_00 M CO 1^00 0^omi--.OCN^^t-~qiM Tj-o CO M roo 00 

\r> invo^^o^ovo t^ t^ tC tCoo ocToo 00 oo" oidioidvo oocT 



OO roOi^^W'O 0)00 CO 
in t-00 O o<, "2 "2^„°9> 

S 6^ d' d o d d d d 



' io\0 O O "O t^ f^ 



la^auiBiQ 



fo^o o M -"tvo oi I 



M ro^o 00 H rO<3C_ . _ _ . _ _ . _ _ 

rj-y3 00 O CO vo t^OO oi -"to 00 w ro lO f^ O cs tJ-vO Ov > 

ro *-r> r^ O 01 -^vO 0» ►-f ro lo t^ O M -^O 0> tH v^ in t^ O csi 't^ O* 

vo m vo\o"\o o o vo t^ t^ !>• t^co oooooooddio\ovdvo o o"o"o 



<N M O O O OvoOOO 
M (S ro ^ ■* too t-^ 
0*M roiOf^O^M ro 



r^vo lo to rh . 



CO O O M M rfj ^ u^^o t^oo Ov 

9, ^_ "t^ 00_ P^ O) rl-vO 00 

r^oo 00 00 CO O'OiO'ddddddd 



■ O t-~ fO OVO (N 00 lO w 



M O O O Ov 
I H, "_ T^.°^. 0_ N ^O^o0_^ O <N ^o r^ Ov 

-co CO CO CO CO ddddddddddd 



00 H --hoo M Thco M -+00 M Tj-t^w tH^O ^t^O for^o cor-- 
OCO O ^ CO M OOO vO •+ CO M OvOO vO ^ CO w O>C0 O "t co H OvC 
CO to t-; Ov IH_ CO -J-'O 00_^ 0_ "^1^ -t lO !>; O W_ CO lOO 00 O "N t+O ?-- 

'+"*^^>oiovo>o io\0 OvOvOvOvO r^t^t^t^ t^OO 00 oO CO 00 c 



cO'O 0> <N vO Ov covO Ov O) vo 
O ■* CN M Ov r^vo ^ oi M Ov 
''i. '7 '■? '^'^^ o, 'I 't^-'^ "^ 
dddddddddd d 



^ ^ ^ t ^ ■*' 



^i^?J,«3 OOCOCOOO OvOOvOvOvO o o o o 
^OO ^ " '^^ '^''O I^'^WOOIOCOO t^^w 

"2 't^„oo_^ 9; "_ ^ "I''^^^ o, '^^ "2 "^ '^°o o, "^^ 
t^ t^ t^ tC r^oo~oo''o3 oo^oo" dddd.dddd 



o 


MOO -*OvlOM t^MOO 

» q. "^ ^ -> f::co^ o^ M_ 

CO-^^'tTt^^lO.O 


M CO >o IN OvvO CO O r^ -+ M OvvO coo i^-*moOion Ovt^-+ 
^OviOMO CNOO ■+Ov>0)HvO <S00 'tOvtOwvO iNOO coOvVO 

CO t^.=<i "^ '-L "^. t ^ ^ o; o. "^„ "3 ^-^^°° q, '-L ^ -t^ '^ o^ 

lO lO to lO lovo \o"mo'"'0"vo"'o'" rC tC tC tC tC tCoo''oc"co"oo'"oo"oo'oo'" 


HIS 


•^ lOvO t^OO Ov O M <v) CO ^ lOVO >.00 Ov O 1-1 N CO '^ lO^O r^OO Ov O w co 
N <N CS IN CS <N cOcOCOcOtOCOcOcOcocO^'t^'t't^'*'<i-'+^":)ir)VO 


CO TJ-IOVO t~-00 Ov O 
lO VO lO vo to lO lOVO 


W 


-IC. -|C» rtiM 

CS CO CO •* Tj- 


-IN HIC 

JO vovOO 


r^ r^oo 00 Ov Ov O 


l 


H M 


^"^ 


CO CO Tj- rt lO lOvO >0 t^ t-OO OO 
<NM<NNNCS(NCMMNW<N 


Ov15 o 














VO 


O vo \0 t^ r^ 


-,lc«MM -.N 
t^ r^oo 00 


00 00 OvOvOvOvO 


"o 


tt 


»i: 


M M CS CM M <N CO 


''co''co"co ^ •* 


•+-=j-io 

















H H H 



saqouj ui ja^aujBiQ 



436 



HORSE-POWER, BELTS AND SHAFTING 



POWER REQUIRED BY MACHINE TOOLS 



Swing 
Inches 

12 

14 
16 
18 

20-22 

24-27 

30 

32-36 

38-42 

48-54 
60-84 



Engine Lathes 

Horse-power 
Average Heavy 



work 
1 
2 

I- I 
1-2 

2-3 

3 
5 

5 - n 
7^-10 

10 -15 

15 -20 
20 -25 



work 

2 
2-3 
2-3 
3-5 
75-10 
7§-IO 

n-T-o 
10 -15 
15 -20 
20 -25 

25 -30 



Axle Lathes 

H.P. 

Single 5- 7i-io 

Double 10-15 -20 

Locomotive axle .... 25 

Wheel Lathes 

Tailstock 
Motor 
H.P. H.P. 
48-in. car wheel. . . 15-20 5 
5 1-60 driv. wheel . . 15-20 5 

79-84 25-30 5 

90 30-40 S-lh 

100 40-50 5-7I 

Quartering attach- 
ment 3-5 

Cylinder Lathes 

H.P. 

40 in 15 

40-in. heavy ...... 20 

48 in 15 

Vertical Boring Mills 

Size Average Heavy 

HP. H.P. 

36-42 in. 5-^7^ 7^-10 

50 in. 71 7i-io 

60-84 in. 7I-10 10 -15 

7-12 ft. 10 -15 30 -40 

14-25 ft. 15 -25 30 -40 



Horizontal Boring, Drilling 
and Milling Machine 



Dia. 
Spindle 


Horse-power 
for Single Spindle 


2,h-Ah 
4I-5I 


7^-10 



5^6^ 10 -15 

For double spindle, use double 
the horse-power. 

Cylinder Boring Mach. 

Dia. Max. Boring Horse- 
Spindle Diameter power 

4 20 ^\ 

6 50 10 

8 40 15 

Miscellaneous 
Loco, rod boring mach. 7i-io 
Car-box boring mach. 
6x12 and 5I X 10'' boxes 5-7^ 
Car- wheel borer 10-15 



Planers 



Size 
24 X 24 in. 
30 X 30 in. 
36 X 36 in. 
48 X 48 in. 
60X 60 in. 
72 X 72 in. 
84 X 84 in. 
100 X 100 in. 



Horse-power 

3- 5 
5-7i 

10-15 

15-20 

20-25 

20-30 

30 

40 



Note. — Normal length of bed 
in feet is about \ the width in 
inches. 

Frog and Switch Planers 
36X 12 in. 30 

48 X 36 in. 30 

Plate Planers 

Niles Nos. 2 and 3 10 

Niles No. 5 IS 

Niles Nos. 6 and 7 20 

Niles No. 8 20-25 



POWER REQUIRED BY MACHINE TOOLS 437 



Rotary Planers 

Dia. Cutter Horse-power 

24- 30 in. 5- 7 1 

36- 42 in. 10 

48- 54 in. 15 

60- 72 in. 20-25 

84-100 in. 30-40 

Shapers 

H.P. 

i2-i6-in. stroke 2 

i8-in. stroke 2-3 

20-24-in. stroke 3-5 

30-in. stroke 5 - 72 

20-in. Traverse-head . . 7^ 

24-in. Traverse-head . . 10 

Crank Blotters 

Stroke Horse-power 

^8 3-5 

10-12 5 

14 5 - 7I 

16-18 7i-io 

20-30 10 -15 

Plain Millers 

Table Feed Cross Feed H.P. 

34 10 7I 

42 12 10 

SO 12 15 

Universal Millers 

Nos. i-i| 1-2 

No. 2 3-5 

No. 3 5 - 7I 

No. 4 72-10 

No. 5 10-15 

Vertical Millers 

Height Under Work 

12-14 in. 5- 7i 

18 in. 10 

20 in. 15 

24 in. 20 

Vertical Slab Millers 

24-in. width of work 7I 

32-36-in. width of work ... 10 
42-\n. width of work 15 



Horizontal Slab Millers 



Width Between 


Horse-power 


Housings 


Average Heavy 


24-30 in. 


7^-10 10-15 


36 in. 


10 -15 20-25 


60-72 in. 


25 75 


Cylindrical Grinders 




Horse-power 


Dia. Wheel 


Average Heavy 


10 m. 


5 1\ 


14 in. 


10 15 


18 in. 


10 15 


Emery Grinders 


No. Wheels 


Dia. H.P. 


2 


6 in. \- I 


2 . 


10 m. 2 


2 


12 m. 3 


2 


18 in. S - l\ 


2 24- 


-26 in. 7i-io 



Misc. Grinders 

Type Horse-power 

Wet tool 2-3 

Flexible swing 3 

Angle cock 3 

Piston rod 3 

Twist driU 2 

Automatic tool 3-5 

Car wheel 30 



Buffing Heads 




No. Wheels 


Dia. 


H.P. 


2 


6 


\-\ 


2 


10 


I -2 


2 


14 


3 -5 



Vertical Drills 

Size H.P. 

12-20 in I 

24-28 in 2 

30-32 in 3 

3^40 in 5 

5c^o in 5 -yi 

Sensitive drills up to ^-in. ^ | 



43S 



HORSE-POWER, BELTS AND SHAFTING 



Radial Drills 

Horse-power 
Size Average Heavy 

3-ft. arm ' 1-2 3 

4-ft. arm 2-3 5 " 7l 

5-6-7ft. arm 3-5 5 - 7i 

8-9-10 ft. arm 5-72 72-10 

Multi.-Spindle Drills 

Size of Drills Up to H.P. 

sV- 4 6-10 spindle 3 

Tt- f 6-10 spindle 5 

TE~ h 6-10 spindle 7^ 

J- i 6-10 spindle 10 

|- I 6-10 spindle 10-15 

2 4 spindle 7^ 

Gear Cutters 

Size Horse-power 
36 X 9 in. 2-3 

48 X 10 in. 3-5 

30-60 X 12 in. 5-75 

72 X 14 in. 7^-10 

64 X 20 in. 10-15 

Cold Saws 

Dia. Saw Horse-power 

20 in. 3 

26 in. 5 

32 in. 71 

36 in. 10-15 

42 in. 20 

48 in. 25 

Hacksaws | 

Bolt Cutters 

Single Horse-power 

I, li, I^ in 1-2 

if , 2 in 2-3 

2I, 3I in 3-5 

4, 6 in. 5-7I 

1, i| in. double 2-3 

2, 2I in. double 3-5 

I, i|, 2 in. triple 3-7^ 

Bolt Pointers 
i|, 2I in 1-2 

Nut Tappers 

I, 2 in. 4-spindle 3 

2 in. 6-spindle 3-5 

2 in. lo-spindle 5 

2 in. nut facer 3 



Pepe Threading and Cutting 
OFF Machines 

Size of Pipe Horse-power 

J- 2 ill. 2 

I- 3 in. 3 

li- 6 m. 3-5 

2 - 8 in. 3-5 

3 -10 in. 5 

4 -12 in. 5 
8 -l8 in. 7I 

24 in. 10 

Hammers 

Size Horse-power 

15- 75 lb. 1-5 

100-200 lb. 5 -75 

Drop hammers require approx- 
imately I horse-power for every 
100-pound weight of hammer 
head. 

100 lb. Bradley hammer 3 

200 lb. Bradley hammer 5 

350 lb. Beaudry hammer 5 

Bulldozers, Forming or 
Bending Machines 

Width Head Movement Horse-power 
29 in. 14 in. 5 

34 in. 16 in. 7I 

39 in. 16 in. 10 

45 in. 18 in. 15 

63 in. 20 in. 20 

Bulldozers (ajax) 

No. 3 5 

No. 4 7I 

No. 5 10 

No. 6 15 

No. 7 30 

No. 9 40 

No. 12 50 

Bolt Headers (hot) 

Size Horse-power 

f-i^ in. S- 7I 

1^2 in. 10-15 

Upsetting Machlnes 

2 in. 7^-10 

3 in. 10 -IS 

5 in. IS -20 

6 in. 20 -30 



POWER REQUIRED BY MACHINE TOOLS 439 



Hot Nut Machines 

Size Horse -power 

^ f in. 5 

f-i in. 72-10 

i|-2 in. 10 -15 

Hyd. Wheel Peess 

Size Horse-power 
100 tons 5 

200-300 tons 7 1 

400 tons 10 

600 tons 15 

Bending and Straightening 
Rolls 

Width Thickness H.P. 

4- 6 in. tV- I 5 

6 in. i^- f 5-15 

8 in. I 25 

10 in. i|-i^ 35-50 

24 in. I 50 

Flue Machines 

No. of Flues Horse- 
Capacity power 
Flue Rattler 250-300 20-30 
Flue Cutter 2-3 
Flue Welder 2-3 

Notching Press (sheet-iron) 

Dia. Punch Thickness Horse-power 
f in. i I 

i- f in. ^-1 2- 3 

f in. I 3-5 

l-i in. ^-f 5 

1 in. I 7§ 

li in. I 72-10 

if in. I 10 -15 

2 in. I 10 -15 
2i in. i^ 15 -25 

Multiple Punch 
4 holes I dia. | plate 7^-10 

Shears 

Horse-power 
Gap Width Cut i Iron Cut J Iron 
30-42 in. 3 5 

56-60 in. 4 75 

72--96 in. 5 10 

Bolt shears 7^ 

Double angle shears 10 

Rotary bevel shears 7I 



Plate Shears 

Metal CutperMin. Stroke H.P. 

I X 24 in. 35 3 in. 10 

1 X 24 in. 20 3 in. 15 

2 X 14 in. 15 4i in. 30 
I X 42 in. 20 4 in. 20 
i| X 42 in. 15 4^ in. 60 
ij X 54 in. 18 6 in. 75 
i^ X 72 in. 20 5^ in. 10 
ijxiooin. 10-12 72 in. 75 

Lever Shears 

Metal Cut Horse-power 

1 X I in. 5 
i^ X i| in. 7§ 

2 X 2 in. 10 
6x1 in. 10 
2I X 2I in. 10 
I X 7 in. 15 
2|x2fin. 15 
1^x8 in. 20 
3I X 3I in. 20 
4I round 30 

Motors Usually Employed 
FOR Cranes and Hoists 

Hoist 
Capacity Speed H.P. 

tons ft. per min. 

5 25 15 

50 25 

10 30 25 

40 40 

15 20 25 

20 15 25 

25 10 25 

IS 33 

30 14 33 

5 aux. 50 25 

10 aux. 25 25 

50 10 40 

5 aux. 50 25 

10 aux. 25 25 

Bridge Trolley 

Capacity Span H.P. H.P. 

tons ft. 

5 60 20 3 

10 80 25 3 

15 80 25 5 

20 80 25 5 

25 80 25 5 

30 80 33 7h 

35 80 40 75-10 



440 



HORSE-POWER, BELTS AND SHAFTING 



POWER REQUIRED FOR 

Band Saws 



Max. width 

of Saw H.P. 

h 

I 3 

2-1^ 3-5 

2I 10 

3I 15 



Dia. Wheel 

30 in. 

34 in. 
36-38 in. 
40-42 in. 
40-42 in. 
40-42 in. 

Cut Off Saws 

Dia. Saw No. of Saws H.P. 

12-14 I 3 

16 I 5 

16 2 7^-10 

30 I 72 



Circular Rip Saws 


14 


I 


5 


16 


I 


7- 


24 


I 


10 


36 


I 


15 



Timber Sizers 

Capacity No. Heads H.P. 

30 X 20 in. 4 50 

20 X 20 in. 4 50 

30 X 10 in. 4 40 

20 X 16 in. 4 40 



Size 
30 X 6 in. 
24 X 6 in. 
30 X 8 in. 
26 X 8 in. 

24 X 6 in. 
16x6 in. 
24 X 8 in. 
30 X 8 in. 

Shapers, i- 
Borers . . . 



Surfacers 

No. Heads H.P. 



1-2 

1-2 

2 



15-20 I s 

15-20 \^l 
30 % 

30 Jk 

5-7|l| 
5- 7^ ^ 

^° Pa 

10 J -^J 

Horse-power 
3-5 
5-7i 

Planers, Matchers and 
Flooring Machines 

Size Heads Horse-power 

9 X 8 in. 4-5 30 

19 X 8 in. 4-s 30 

24 X 8 in. 4-5 40 



•2 sp 



PLANING-MILL EQUIPMENT 

Size Heads Horse-power 

30 X 8 in. 4-5 40 

24X 12 in. 4-5 40 

30x12 in. 4-5 40 

Outside Moulders 

Capacity No. Heads Horse-power 

4 X 4 in. 1-2 5 

4x4 in.. 3-4 7^ 

6 X 4 in. 1-2 5 

6 X 4 in. 3-4 71 

8 X 4 in. 4 10 

10 X 4 in. 4 15 

12 X 5 in. 4 20 

14 X 6 in. 4 20 

Inside Moulders 

8x4 in. 4 15 

10 X 4 in. 4' 15 

10 X 6 in 4-5 20-30 

15 X 4 in. 4-5 20-30 

Jointers 



S-12 in. 
16-24 in. 
30-36 in. 



Tenoning Machines 

No. Heads 

5^ X 14 in. I 3-5 

5|xi5in. 2 5 

23 X 9 in. 2 7I 

54 X 4§ in. 4-8 10 -IS 

78 X 4^ in. 4-8 10 -15 

Gainers 7j-io -15 

Belt Sanders 

Width of Belt Horse-power 

6-14 in. 2-3 

18 in. 5 

Column Arm 



Length of 
Arm 
4-10 ft. 



Dia. of 
Disks 



Horse-power 
8 in. 3 

Drum Sanders 

Length of Drum Horse-power 

30 in. 



36 in. 
42-48 in. 
54-60 in. 
72-84 in. 



7h 
10 

IS 
20 

30 



POWER REQUIRED FOR MACHINE TOOLS 441 



Group Driving of Machines 

There are many shops where group driving will be found more 
desirable than the use of individual motors, both as to first cost 
and maintenance. This is particularly true where the machines 
are comparatively small and run intermittently, as the cost of 
motors will be much less. 

Friction load of 2^ to 3-inch shafting, with bearings 8 to 10 feet 
and running at 150 to 200 revolutions per minute, is about i horse- 
power for ever}^ 30 feet of shafting. This includes the friction of 
countershafts of the machines driven by it. 

In group driving it is usually perfectly safe to select a motor 
having a rated capacity of from 25 to 30 per cent, of the total power 
required for the machines in the group. 

Power Required for Punching and Shearing 

Experiments tend to show that with steel plates of 60,000 pounds 
tensile strength, the metal is all sheared when the punch has passed 
^ through the plate. The following formula by L. R. Pomeroy takes 
this into account and also allows the motor and efficiency of 80 per 
cent, and the punching machine 75 per cent. 

When T = FuU thickness of plate. 

D = Diameter of hole punched. 

N = Number of holes punched per minute. 

P = Horse-power required to drive machine. 

'nxDXN 
3-78 

Taking a |-inch hole in a ^-inch plate, the power required to 
punch 30 per minute would be 

iXiX3o 3.75 , ^ , 

r-^^ = - — r or about I horse-power. 

3-78 3-78 

Pressure required for shearing = Length of cut X thickness in 
inches X shearing strength of material. Dies with "shear" reduce 
this J to ^. 

Power Required to Remove Metal 

The power required to remove metal depends on the amount of 
metal removed per minute and the nature of the cutting tool. With 
a cutting angle of 75 to 80 degrees, tests show that for mild steel 
of 40-point carbon one horse-power will remove 1.5 cubic inches of 
metal per minute. 

For average conditions and with tools as ordinarily used, tests 
show that to remove one cubic inch of metal per min. requires the 
amount of power shown in the table. 



442 HORSE-POWER, BELTS AND SHAFTING 

Brass and similar alloys 0.2 to 0.3 H.P. 

Cast iron 0.3 to 0.5 " 

Wrought iron ) ^ u 

Mild steel (0.30% to 0.40% carbon) . . ) 

Hard steel (0.50% carbon) i.oo to 1.25 " 

Very hard tire steel 1.50 " 

Two important factors enter into the problem of power for driving 
machines. These are the Time Factor and the Load Factor. 



Time Factor = 
Load Factor = 



Actual Cutting Time 



Total Time to Complete Operation 

Average Daily Load 
Full Load Rating of Motor 



Many tests give the following load factors: 

The average load factor for motors driving lathes is from 10 
to 25 per cent. On some special macliines, as driving wheel and 
car wheel lathes, the cuts are all heavy, which increases the average 
load factor to from 30 to 40 per cent. 

For extension boring mills, 5 horse-power motors are used to move 
the housings on from 10 feet to 16 feet mills, 7I horse-power for 
from 14 feet to 20 feet mills and 10 horse-power for from 16 feet to 
24 feet mills. The load factor of the driving motor on boring mills 
averages from 10 to 25 per cent. 

The load factor of motor-driven drills is about 40 per cent, when 
the larger drills applicable thereto are used. If the smaller drills 
are used the load factor averages 25 per cent, and lower. 

For the average milling operations the load factor averages from 
10 to 25 per cent. On slab milling machines where large quantities 
of metal are removed it will average from 30 to 40 per cent. 

The work on this class of machinery is usually light and much 
time is required in making adjustments. Hence the load factor is 
rarely higher than 20 per cent. 

On planers the load factor averages between 15 and 20 per cent. 
The motor must be large enough to reverse the table quickly, yet 
this peak load occurs for such short intervals that it does not in- 
crease the average load per cycle very much. 

The work done on shapers is of a varying character. With light 
work the load factor will not exceed from 15 to 20 per cent.; with 
heavy work, the load factor will be as high as 40 per cent. 

The conditions with slotters are similar to those on shapers. 



Horse-Power to Drive Machines 

Extensive experiments by L. R. Pomeroy show that the horse- 
power required equals the Feed per rev. or stroke X Depth of 



POWER REQUIRED TO REMOVE METAL 443 

cut in inches X Cutting speed in feet per minute X 12 X Number 
of tools cutting X a Constant which depends on the material. This 
checks up fairly well with actual motor tests. The constants given 
are: 

Cast iron 0.35 to 0.5 

Wrought iron or soft steel 0.45 to 0.7 

Locomotive driving wheel tires 0.70 to i. 00 

Very hard steel i-oo to i.io 

Handhng this in another way, Charles Robbins of the Westing- 
house Electric & IManufacturing Co. gives: The horse-power = 
Cubic inches removed per minute X a Constant. These constants 
are: 

Brass and similar alloys 0.2 to 0.3 

Cast iron 0.3 to 0.5 

Wrought iron 0.6 

Mild steel (0.30 to 0.40 carbon) 0.6 

Hard steel (0.50 carbon) i.oo to 1.25 

Very hard tire steel 1.50 

These represent average conditions with the cutting tools ordinarily 
used. 

A brief summary of the studies by Mr. Robbins gives interesting 
data on various machines. These give factors as follows: 





Time 
Factor 


Load 
Factor 




44% 

41 

54 

50 

55 


27% 


Radial drilline' machine 


10 


Portable millinsf machine 


55 


Portable slottinsf machine 


12 


Planers 









L. R. Pomeroy also gives a method of determining the horse-power 
required by the belt used to drive the machine. The formula is: 

Hp. = Thickness of belt in inches X Width of belt in inches X 
Diameter of pulley in inches X Revolutions per minute X 
Constant for kind of belt. 

These constants are: 

Leather belt 0.0062 to 0.0098 

Cotton belt 0.0036 to 0.0068 

Rubber belt 0.0050 to 0.0082 



STEEL AND OTHER METALS 

HEAT TREATMENT OF STEEL 

The theory of the heat treatment of steel rests upon the influence 
of the rate of cooling on certain molecular changes in structure occur- 
ring at different temperatures in the solid state. These changes are 
of two classes, critical and progressive; the former occur periodically 
between certain narrow temperature limits, while the latter proceed 
gradually with the rise in temperature, each change producing alter- 
ations in the physical characteristics. By controlling the rate of 
cooling, these changes can be given a permanent set, and the physical 
characteristics can thus be made different from those in the metal 
in its normal state. 

The highest temperature that it is safe to submit a steel to for 
heat-treating is governed by the chemical composition of the steel. 
Pure carbon steel should be raised to about 1650 degrees Fahr., 
while some of the high-grade alloy steels may safely be raised to 1750 
degrees Fahr., and the high-speed steels may be raised to just below 
the melting point, usually from 2000 to 2150 degrees Fahr. It is 
necessary to raise the metal to these points so that the active cooling 
process will have the desired effect of checking the crystallization of 
the structure. 

Methods of Heating 

Furnaces using solid fuel such as coal, coke, charcoal, etc., are the 
most numerous and have been used the longest. These furnaces 
consist of a grate to place the fuel on, an arch to reflect the heat and 
a plate to put the pieces on. The plate should be so arranged that 
the flames will not strike the pieces to be heated, and for that reason 
some use cast-iron or clay retorts which are open on the side toward 
the doors of the furnace. 

Liquid fuel furnaces, which have open fires and which use liquid 
fuels, are not' very numerous at present, but their use is increasing, 
owing to the ease with which the fire is handled and the cleanlmess 
as compared with a coal, coke or charcoal fire. 

Crude oil and kerosene are the fuels generally used in these fur- 
naces, owing to their cheapness and the fact that they can be easily 
obtained. These fuels are usually stored in a tank near the furnaces 
and are pumped to them or flow by force of gravity. 

Heating in Liquids 

Furnaces using liquid for heating have a receptacle to hold the 
liquid, w^hich k heated by coal, oil, gas or any other economical 
means; the liquid is kept at the highest temperature to which the 
piece should be heated. The piece should be heated slowly in an 
ordinary furnace to about 800 degrees, after which it should b^ 



THE HARDENING BATH 445 

immersed in the liquid bath and kept there long enough to attain the 
temperature of the bath and then removed to be annealed or hardened. 

The bath usually consists of lead, although antimony, cyanate of 
potassium, chloride of barium, a mixture of chloride of barium and 
chloride of potassium in the proportion of 3 to 2, mercury, common 
salt and metallic salts have been successfully used. 

This method gives good results, as no portion of the piece to be 
treated can reach a temperature above that of the liquid bath; a 
pyrometer attachment will indicate exactly when the piece has 
arrived at that temperature, and its surface cannot be acted upon 
chemically. The bath can be maintained easily at the proper tem- 
perature and the entire process is under perfect control. 

When lead is used it is liable to stick to the steel unless it is pure 
and retard the cooling of the spots where it adheres. Impurities, 
such as sulphur, are liable to be absorbed by the steel and thus afifect 
its chemical composition. With high temperatures lead and cyanate 
of potassium throw off poisonous vapors which make them prohibitive, 
and even at comparatively low temperatures these vapors are detri- 
mental to the health of the workmen in the hardening room. The 
metallic salts, however, do not give off these poisonous vapors, and 
are much better to use for this purpose, but many times the fumes 
are unbearable. 

Gas as Fuel 

Furnaces using gaseous fuel are very numerous and are so con- 
structed that they can use either natural gas, artificial gas, or pro- 
ducer gas. They are very easy to regulate and if well built are 
capable of maintaining a constant temperature within a wide range. 

In first cost this style of furnace is greater than that of the solid 
fuel furnaces, but where natural or producer gas is used the cost of 
operating is so much less that the saving soon pays for the cost of 
installation. Illuminating gas, however, is more expensive than the 
solid fuels and is only used where high-grade work demands the best 
results from heat treatment. 

COOLING THE STEEL 

Cooling apparatus is divided into two classes — baths for hard- 
ening and the different appliances for annealing. 

The baths for quenching are composed of a large variety of ma- 
terials. Some of the more commonly used are as follows, being 
arranged according to their intensity on 0.85 per cent, carbon steel: 
Mercury; water with sulphuric acid added; nitrate of potassium; sal 
ammoniac; common salt; carbonate of lime; carbonate of magnesia; 
pure water; water containing soap, sugar, dextrine or alcohol; sweet 
milk; various oils'; beef suet; tallow; wax. These baths, however, 
do not act under all conditions with the same relative intensity, as 
their conductivity and viscosity vary greatly with the temperature. 

With the exception of the oils and some of the greases, the quench- 
ing